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Gun Glossary - Letter C
Index of Firearm & Gun Terminology

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Letter - C Page Updated: 08 March 2003

CALIBER: Term of measurement used to determine the size and type of ammunition used in a firearm. Caliber is the nominal diameter of the projectile (bullet) as used in a rifled firearm; or the diameter between lands in a rifled barrel.  Therefore: Caliber is the inner diameter of a guns bore (barrel) or the  measurement of the inner dimension of the guns barrel. 

Caliber Confusion - Caliber Context

Warning: Use of improper ammunition is dangerous & may lead to severe injury or death.

SAFETY FIRST: You must use the correct caliber or gauge of ammunition at all times. You must use ammunition that is  designed and engineered specifically for your particular firearm. Loading the wrong ammunition into any firearm is very dangerous and may lead to severe injury or death. You could literally blow your head off. You could kill or maim an innocent bystander. You could blind yourself or cause irreparable damage to your body. 

Seek Professional Help

Seek Professional Help: If you are new to firearms ownership and shooting or if you have a new gun with unfamiliar features, don't be afraid to admit your lack of knowledge. Please ask for help. Start by reading the owners manual, then ask a certified firearms instructor to assist you. Schedule a class at the local shooting range. Do not ask a cop or a former military person for help unless they are also a Certified Firearms Instructor.

See Also: "Cops are People with Guns... Cops Are Not Gun People".

Identify Caliber & Gauge: To identify a firearm by caliber or gauge, carefully unload the firearm, keep the action open, keep your finger off the trigger, keep the firearm pointed in a safe direction and visually inspect the receiver or the barrel of the gun to determine the specific caliber. It will be engraved or stamped into the gun

Design Function: Guns are designed to safely fire and cycle a specific size cartridge or a specific "caliber" of ammunition. All modern firearms are required by law to have the caliber stamped or engraved into the receiver or barrel. Your gun should have the specific caliber or gauge engraved or stamped into its receiver or on the barrel. The exception being some very old firearms and some custom "Wild Cat" guns, that have been re-chambered. Most "Wild Caters" simply over stamp the new caliber onto the receiver or barrel.

Another Exceptional Exception: Some guns can safely fire more than one caliber. But only when multi-caliber capability is an engineered design function. Your owners manual and or the manufacturer can help you with this. There are several medium and large bore revolvers that have the same nominal bore diameter and by virtue of the use of cylinders (not barreled chambers) can safely fire different lengths and strengths of ammunition that is of the same bore diameter.  

Warning: If you have an old revolver and some "Duffs" (Typically an X-Marine or Cop) tells you - "You know dude - you can fire X-caliber in that Y-gun as well as shooting XYZ". Stop and check the facts. The fact that it will fit and that it can fire does not mean it should be used and it might blow up the next time you pull the trigger. This is particularly true of old revolvers in the .38 caliber when firing 357 Magnum and .38-Special cartridges.  Seek professional help.

Modern Rifles Also Exceptional: There are several long guns with interchangeable barrels. Notable in this field are the long guns from Sauer, SIGArms and Blaser. These guns can change caliber by installing a new barrel (and in some case) a new bolt head. These "Fine Arms" are designed to safely fire and cycle multiple calibers but only after a barrel assembly and bolt a changed. Once you swap the interchangeable barrel, the specific caliber and cartridge size will be stamped or engrave on the barrel. 

Re-Chambered Military Surplus: Many older military surplus guns are re-chambered to use modern ammunition or ammunition that is common in the American market. An example being the MAS-49/56 which was originally chambered in the 7.5 mm French cartridge and is often sold in America as a surplus gun re-chambered to 7.62 NATO or .308 Winchester. This is done for marketability and to make use of modern ammunition that is inexpensive and widely available. These Re-Chambered gun will have an OVER STAMP on the receiver or barrel indicating the new caliber. If your gun has two calibers stamped on it, the New / Current caliber will be stamped in larger letters.

Got Specs? Exacting Ammunition Safety Specifications are created and maintained by SAAMI - the Sporting Arms and Ammunition Manufacturers Institute  -  SAAMI Sets Product Standards for Firearms and Ammunition. One of the most important standards is the amount of "Chamber Pressure" a particular cartridge creates inside the action of a gun when fired. As the bullet or projectile is literally created by a small contained explosion and violently propelled from the barrel by "Rapidly Expanding Gasses", this internal pressure must be closely regulated and the firearm must be designed to withstand these tremendous internal pressures.

SAAMI is on the Web at URL:

Light - Defensive - Heavy

Light Calibers: These are very common calibers ranging from .22 to .32 caliber are considered "light" and are best suited for target shooting and small game. In long guns they are great for plinking and for small game and or killing rodents. The most common plinking round in the world is still the .22 caliber. It is also a great "starter / trainer" gun due to its low cost, ease of use (low noise low felt recoil) and the simple fun-factor.

Medium / Defensive Calibers: Calibers from .38 to .45,  which include the most common and very popular 9mm, the newer .40 Auto and Professional Grade .357 SIG, as well as the antiquated and over rated .45 ACP are commonly selected by law enforcement agencies and American gun owners as "defensive calibers". [ With fewer and fewer agencies selecting the .45 ACP due to its high felt recoil and low magazine capacity ] Medium Defensive Calibers are powerful enough to serve with reasonable reliability in a defensive role. - See Klingon Disruptor below - 

"Heavy" Sporting Calibers: Calibers such as the .44 magnum, .454 Casuals and various .50 caliber hand guns  produce incredible amounts of energy with the accompanying recoil and they may require special care with respect to a safe shooting area and use. They are best suited for sport shooting and for hunting large game or for use as a back-up side arm when traveling in dangerous game country. many trappers and hunters in "Grizzly Bear" country carry a .44 magnum revolver like the venerable Smith & Wesson Model 624 or Modern Model 629.

USA All the Way: In the U.S., caliber is traditionally expressed in hundredths of inches, e.g., .22 or .30 caliber which are .22 inches = 22/100 of an inch and .3 inches = 33/100 of an inch in diameter respectively.  A .50 caliber is .5 = 50/100 = 1/2 inch in diameter. .25 Caliber is 1/4 of an inch, .30 Caliber is about 1/3 of an inch and so on. 

Damn Foreigners: To make things more confusing in Britain, caliber is often expressed in thousandths of inches, e.g.,  Caliber .270 Remington or Caliber .465 Wesley. Where .270 Caliber is equal to .27 of an inch 270/1000 of an inch & the powerful .465 being equal to .465 inches or 465/1000 of an inch.

Shotguns are measured in Gauge not Caliber

GAUGE: The system of measurement for the internal bore diameter of a shotgun or smooth-bore firearm. The common measurement for the "caliber" or bore size of a shotgun. In this case, the term bore refers to the inner diameter of the barrel. Gauge is determined by counting the number of round lead balls of specific bore diameter that are equal to one pound or 16 ounces.  No not kidding. This is an old and antiquated method of measurement that most people do not know about. Thus 12-gauge or 12 bore means that 12 pure lead balls of 12 gauge diameter will weigh one pound.  The sole exception to this is the .410 shotgun, which has a diameter of .41 inches (i.e., .410 caliber and is actually 68-gauge).  Note: Sometimes GAUGE is spelled GAGE.


Gauge Diameter Metric
10-Gauge = .775 inches = 19.3mm
12-Gauge = .729 inches = 18.2mm
16-Gauge = .662 inches = 16.8mm
20-Gauge = .615 inches = 15.7mm
28-Gauge = .550 inches = 13.8mm
*68-Gauge = .410 inches = 12.6mm

 *More caliber confusion for us to ponder. The .410 Gauge Shotgun is not really a gauge, except by convention. In this exception, .410 is the actual diameter of the bore in decimal (.410 inches) so technically is a .410 caliber smoothbore and a 68-Gauge Shotgun. 

The Gauge/Bore system is also used to describe the internal barrel diameter of large-bore, 19th century, English, single-shot and double-barrel black powder rifles.

Military Affairs: In the U.S. Military and most other countries, caliber is commonly expressed in millimeters. 9mm is 9mm in diameter. 5.56 millimeter (mm) is 5 point 56 millimeters (5.56) in diameter. e.g., the NATO 5.56 mm cartridge as used in the U.S. M16 rifle and most NATO small arms. 

Big Guns: In artillery and large caliber field guns and in some heavier military weapons the nominal diameter of the inner dimension of the barrel or tube (mortar) is also expressed in millimeters, e.g., the 81 mm mortar, the 105 mm howitzer (light), the 155 mm howitzer (medium or heavy).  German 88's had a bore diameter of 88 millimeters, the M1A2 Abrams Main Battle Tank has a 120 mm main gun, a 20 millimeter cannon has a bore diameter of 20 millimeters and so on.

In The Navy: Naval guns’ caliber refers to the barrel length as a multiple of the bore diameter. A 5-inch, 50-caliber naval gun has a 5-inch bore and a barrel length of 250 inches. Large Naval gun are measured in inches as above with massive gun as large as 16 and 19 inches of bore diameter.  U.S. battleships have 16 inch guns capable of firing a Volkswagen sized projectile well over 20 miles.

Suitability to Task: As a loose rule for beginners, the larger the decimal fraction, the "higher" the caliber the larger and in some cases the more powerful the ammunition. One can not assume that a big bullet or using a "bigger" caliber means that you are using a more powerful or most importantly a more effective firearm. The factors for determining "Power" are complex and include not only the diameter of the projectile but also the speed or velocity of the projectile, the weight of the bullet or projectile and for effectiveness, to some degree the shape and composition of the projectile.

To put caliber in a general context, a .22 caliber is the smallest common caliber used in America and around the world (with some inroads made of late by the .177 caliber.) This is a "Plinking Round" suitable for taking very small game and rodents. The most common hand gun caliber is the 9mm and the most common rifle cartridge caliber in the U.S.A. is the 30-06.  Again, shotguns are measured in gauge and the most common shotgun "gauge" in America is the 12-gauge.

RTFM: Read The Frigging Manual - If you really want to know anything you must study. Learning about guns is no different than learning about anything. Get read up then seek training and advice from a firearm instructor. Thousands of books and now tens of thousands of online documents exist in the field of arms. You can also get invaluable help (mostly free of charge) from firearms manufacturers and ammunition makers. They can help you select the proper tool for the job. Firearms, especially hunting rifles and specialized sporting guns are in fact tools. Some sports require super specialized arms and other shooting sports use and even require the use of "out of the box" guns. Guns you can buy at your local gun shop or even at Wal-Mart. The shooting sports association or governing body and their gun clubs normally have a beginners guide and they can all refer you to the published standards for their respective shooting discipline.

For effective, humane and ethical hunting practices, the caliber and bullet size are not the only factors. One should also consider the size and type of the animal being hunted, the range or distance you expect to engage the animal from and the type of terrain. With these variables one can then select the type and construction of the projectile (bullet) and the type cartridge needed. Study to select the proper bullet composition and design so you will be a humane, ethical and effective hunter. I would add that that means passing on shot that are out of range for your skill, your gun or the weather conditions. Most effective shots are taken from 250 yards or less.

For Example: .308 Winchester is a great all around cartridge, but it would be ineffective and unethical to use a military surplus cartridge (actually a 7.62 NATO) with a full metal jacket (FMJ) on a game animal. The FMJ military style projectile is designed to pass through a target with little or no bullet expansion, which would result in a ice pick sized hole and a wounded animal. The exact same caliber with a game style bullet will properly expand imparting most of the remaining energy into the animal, casing immediate incapacitation or death, killing the animal in a quick and humane manor.

For Defensive Use: The most important factors in surviving a gun fight are Mind Set, Tactics and Shot Placement. All things being equal, if you are using a hand gun to defend yourself and your family, as most people do, you will be better off with a caliber that is easy to control for quick and effective follow up shots. There is no place in most cases for a hand cannon. If you are going to have a gun fight with a bulldozer or a rhino use a dangerous game rifle. If a hand gun is your family defense option, pick one that all the adult family members can use. You should also consider buying a good 12-guage or for the whole family, a good 20-guage shotgun.  Many are available in gun shops for under 200 dollars. A revolver is also an excellent choice for a home defense gun as it requires very little training and is almost infallible.  If it is traditional SA/DA revolver with the cylinder loaded, all you have to do is pull the trigger. The more complicated guns require additional training.

Klingon Disruptor Not!  Hand Guns are practical and easy to carry. They are not elephant guns. So, I remind you that it is a hand gun not a Klingon Disruptor and unlike what your idiot (former Marine or current Police Officer) and general duff-brain, know-it-not, brother-in-law tells you, you can not make up for a small brain with a big bullet.  Next time some idiot starts telling you their .45 ACP is better than your girly-man 9mm, ask them how many gun fights they have been in? How many confirmed kills they have with a hand gun? And then when they look at you with that "I am missing some DNA look" on their face, tell them to come and visit Gunnery Network for the unabridged truth.  I carry a 9mm SIG P226 and I can tell you it works. The most important factors in winning a gun fight are 1. Mindset. 2. Tactics. 3. Shot placement. 

I have trained hundreds of shooters and most of them are much more effective with a well fitting 9mm semi-automatic pistol than they are with any of the larger more macho alternatives. I say "If you are not man enough to carry 9mm you are just not man enough".  Remember this "You can not compensate for a small brain with a big bullet!"

Note: Shotgun Ammunition is measured in GAUGE. See Gauge: Gun Glossary - Letter G

CALIBERS of the CIVIL WAR: Prior to the outbreak of the Civil War, the arsenals of the United States Army did not carry any rifled cannon on their inventory.  Although several rifled cannon had been produced, the army continued to depend on smoothbore artillery weapons.  It was a common practice to refer to these weapons as “pounder” according to the weight of the solid projectile fired from the tubes.  This term has led to confusion when collectors interchange it with the weight of a projectile.  The correct term usage is “pounder” for the weapon and “pounds” for the shot.

Civil War Caliber Confusion
The Caliber-to-Pounder Relationship

In addition to the weight nomenclature, smoothbore weapons were also classified by the bore diameter in inches (also known as caliber).  This worked fine for the smoothbores since the diameter of the bore and the diameter of the shot remained constant for a given weight, i.e. the bore diameter of a 32-pounder was always 6.4 inches.

Soon after the Civil War began, the army realized the advantages of having rifled weapons that could fire elongated projectiles across greater distances.  In addition to ordering new weapons, the government also set about to rifle the older smoothbore guns.  Now, even though the bore diameter remained the same, the weight of the projectile could be changed by being lengthened or shortened.  The alteration of smoothbores, along with the projectiles, led to confusion during the Civil War, as well as being confusing for today’s collectors and students.

Charles T. James
General Charles T. James

A common weapon that was re-bored was the bronze Model 1841, also known as a 3.67-inch gun or a 6-pounder.  This cannon was converted from a smoothbore to a rifled weapon by the James system of rifling, developed by General Charles T. James to accommodate his new shell, which required special rifling.  Because the rifling allowed a larger shell to be fired, about 12 pounds, these guns were incorrectly referred to as 12-pounders.  In some reports these guns were also referred to as “James Rifles,” which is also misleading since there was also a 14-pounder (3.8-inch) bronze field piece manufactured for General James in 1861, which carried the “James Rifle” nomenclature.

The 3.67- and 3.8-inch bronze Model 1841 pattern had a bore length of 57.5 inches and fired a projectile with a powder charge of 1.25 pounds.  The ammunition was short and light, usually of the  James and Schenkl pattern. 

The 900 pound U.S. Model No. 1 carriage common with these tubes could not withstand the violent recoil a higher charge for heavier projectiles produced.  Carriage and tube together weighed 1,785 pounds.  Even with the light weight tube, many of these carriages failed in the field and, in 1864, the carriage was redesigned to make it stronger.
It should be noted that many of the 3.67-inch smoothbore guns were re-bored to 3.8-inches in order to make the bore interior completely smooth before rifling.  As a result, most of the true 3.67-inch rifles in existence today, were manufactured as rifles instead of being converted.  Guns made by Ames Company in Massachusetts, Miles Greenwood of Ohio (Eagle Iron Works), and William Marshall and Company of St. Louis, Missouri, are examples of this type. 

The image to your right is an example of a Miles Greenwood manufactured Model 1841 6-pounder (3.67-inch caliber) smoothbore bronze cannon that was re-bored to 3.80-inches with James rifling.

Click on image to see more images
Model 1841 6-Pounder

It should be noted that many of the 3.67-inch smoothbore guns were re-bored to 3.8-inches in order to make the bore interior completely smooth before rifling.  As a result, most of the true 3.67-inch rifles in existence today, were manufactured as rifles instead of being converted.  Guns made by Ames Company in Massachusetts, Miles Greenwood of Ohio (Eagle Iron Works), and William Marshall and Company of St. Louis, Missouri, are examples of this type.

Robert P. Parrott
Robert Parker Parrott

Another confusing caliber to pounder relationship exists when discussing the Parrott weapons.  These cannon, designed by Robert Parker Parrott, were manufactured in several sizes during the war.  The Parrott traditionally is referred to by its numerical pounder designation, but this can be misleading.

For example, the same 8-inch Parrott rifle was referred to as a “200-pounder” by the army and as a “150-pounder” in the navy.  The confusion existed because the original 200 pound projectile had been shortened, thus reducing the weight to 150 pounds.  The navy carried the new designation while the army retained the older.  The 10-inch Parrott was known as a 300-pounder, even though it actually fired a shell weighing about 250 pounds.  The 6.4-inch Parrott, known as a 100-pounder, fired several types of solid shots and bolts, many of which varied from the designated weight.

The 10-pounder Parrott rifles were manufactured with two different bore diameters.  An early war model had a 2.9-inch bore, while the model produced in 1863 had a 3-inch bore.  Yet both of these cannon are commonly referred to as 10- and, sometimes, 12-pounders, even though the ammunition used varied in weight.  The 2.9-inch caliber Parrott rifle is, and should be, referred to as a 10-pounder Parrott rifle and the 3-inch caliber should be referred to as only a Model 1863 3-inch caliber Parrott rifle, not a 10-pounder Parrott rifle. 
The 20-pounder Parrott gun, although having the same bore diameter of the Model 1841 (3.67-inch),  had a bore length of 79 inches.  This allowed it to fire a 20-pound projectile with a two-pound powder charge, nearly twice as powerful as the Model 1841, yet the same diameter. The carriage (a Number 3) and tube of this Parrott weighed 2,850 pounds total, more than a half-ton heavier than the Model 1841 3.67-inch assembly.

The 20-pounder Parrott could fire the light (12 to 14 pounds) 3.67-inch projectiles of the Model 1841, with proper adjustments in the range tables.  However, the 3.67-inch Parrott projectiles (20-pounds) could not be fired from the Model 1841 without fear of a failure of the tube and carriage.

20-pounder Parrott Rifle
20-Pounder Parrott Gun

The difference in the weight of the 3.67-inch projectiles was due to differences in the sabots and lengths of the projectiles.  The 20-pound Parrott projectiles had short bodies and a short expanding cup sabot.  The solid iron Parrott projectile weighed between 19- and 20-pounds.  The 3.67-inch Parrott shells were comprised of longer bodies, which allowed for more room for filler powder or case shot, and also weighed nearly 20-pounds fully charged.  Range tables used in a mixed artillery unit (all three projectiles being used) had to contain separate elevations, ranges, and flight times, so fuzes could be adjusted accordingly.

Classification of Parrott rifles was originally stamped on the face of the muzzle with both designations – i.e. “3.67-in. 20 Pdr.”  However, because of the confusion existing over the weight of the projectiles, the larger guns soon became known by the bore diameter.  This should be kept in mind by the collector or student when attempting to determine which projectiles were fired by which weapon.

Even though the Eastern armies had standardized field artillery batteries by late 1862, the Western armies, along with the Confederates, used a mixture of guns throughout the war.  Therefore, it is not unusual for the collector to find a mixture of light and heavy 3.67-inch projectiles at late war battlefields.

Early collectors once classified all 3.67-inch projectiles as being 20-pounder Parrott ammunition. However, the final determination must be made based on the weight, length, and sabot of the shell.

CAN: Slang for Silencer or Sound Suppressor:  See Silencer.

CANNELURE: A groove (or grooves) cut around the circumference of a bullet. These grooves, usually one to a bullet, provide the best means of securely crimping the case mouth into the bullet.

CARBINE: A rifle with a relatively short barrel. Today's Carbines like the AR-15 variants typically have a 16 inch barrel.  Any rifle or carbine with a barrel less than 16" long must be registered with the Bureau of Alcohol, Tobacco and Firearms in accordance with the National Firearms Act (NFA).  Shotguns with barrels less than 18" long fall into the same NFA category.

M4 Carbine
M-4 Carbine

The M4 Carbine is a lightweight, gas operated, air cooled, magazine fed, selective rate, shoulder fired weapon with a collapsible stock. 

Basically an improved,  shortened variant of the M16A2 rifle, the M4 Carbine provides the individual soldier operating in close quarters the capability to engage targets at extended range with accurate, lethal fire. 

ArmaLite AR-10A4 Carbine

  Exceptionally strong and lightweight synthetic fiber made especially by carbonizing acrylic fiber at high temperatures.

CARBON 15:  AR-15 type rifles and pistols manufactured by Professional Ordinance Corporation  using carbon fiber composite materials for the upper and lower receiver and parts of the butt stock and fore grip.

The Carbon 15 Type 97
Space Age Composites Meet Iron Age Firearms

Carbon Fiber Composite Technology had its birth in the early 1960's, as the new Aerospace industry required more advanced materials.  More recently, in addition to areas such as the Space Shuttle and the Stealth Fighter aircraft, Carbon Fiber Composites are being used for applications such as "Indy" and "Formula 1" competitive automobiles providing an advantage over the competition. 

Carbon fiber composite technology made its advent into the firearms industry in 1996 at Professional Ordnance Corporation, and it is implemented today in the Carbon 15 series of firearms.

CARTRIDGE:  A single, complete round of ammunition. - Commonly misnamed "bullet" it consists of 4 parts. The Cartridge components are the Bullet, the Case, the Powder and the Primer.  See component detail in the diagram below. Shotgun and Field Artillery ammunition are typically called shells not cartridges.

Typical Handgun Cartridge

1. The Primer, a smaller cup, set in the end of the case, containing a material which ignites when struck by the firing pin of the firearm. 

2.  The Powder, a chemical compound which burns rapidly, producing a mass of gas which expands, propelling the bullet.   Also called Gun Powder.

3. The Case, a metal tube shaped container of steel, tin or brass which contains the bullet, the  primer and the powder.

4. The Bullet, a projectile normally made of lead and which may be coated with a thin jacket of copper.

Any cartridge intended for use in rifle, pistols, and revolvers that has its primer central to the axis at the head of the case. Note: Most cartridges, including shot shells, are center fire with the exception of 22 caliber rim fire ammunition. If you were to look at the bottom of a center fire cartridge, you would see a small circle in the middle of the base, hence, "center fire." There are a few rim fire ammunition calibers besides the 22, but they are rare and not widely available.

CARTRIDGE, MAGNUM:  Any cartridge or shot shell that is larger, contains more shot, or produces a higher velocity than standard cartridges or shot shells of a given caliber or gauge.

CARTRIDGE, RIM FIRE:  A cartridge containing the priming mixture in the rim of the base, usually a 22 caliber.

CARTRIDGE, SMALL BORE:  A general term that refers to rim fire cartridges. Normally 22 caliber ammunition used for target shooting, plinking, and small game hunting.

CAPACITY:  Number of cartridges or rounds of ammunition a firearm will hold.

CASE, CASING: The metal, plastic or paper container which holds all of the components of a round of ammunition. The envelope (container) of a cartridge. For rifles and handguns it is usually of brass or other metal; for shotguns it is usually of paper or plastic with a metal head and is more often called a "shell."  Case 2: The case is the capped metal cylinder that holds all of the other parts together. Most often the case is made of brass. When a cartridge has been fired, the bullet leaves the gun through the barrel, and the case remains behind. It is now a "spent" or empty case, and is commonly referred to simply as "brass". Shooters who reload their own ammunition place a certain value on brass, and you are generally expected to clean up your own brass when you are finished shooting.

CASE NECK BRUSH: The metal brush and handle used to clean the inside of case necks.

CASE TRIMMER: A device used to remove excess material from a case mouth. Metallic cases stretch after extensive reloading and firing because the brass flows forward. These cases must be trimmed back.

CASE TRIMMER PILOT: The pilot guides the cutting portion of a case trimmer by fitting inside the neck of the case to be trimmed.

CAST BULLET: Bullets for center fire rifle or pistol which are cast from lead alloy. Muzzle loading projectiles and shotgun slugs are cast in pure lead.

CCL: Acronym for Concealed Carry License, as in CCL permit or CCL holster.  a.k.a. CCW.

CCW:  Abbreviation for Concealed Carry Weapon, as in CCW permit or CCW holster.

CENTER FIRE - CENTER FIRE: Term used to indicate and describe a type of ammunition cartridge with its primer located in the center of the base of the case.  Center fire can also be written Center Fire.

CENTER FIRE CARTRIDGE:  A design of ammunition in which the primer is centrally located in the base of the cartridge case.  Center fire cartridge cases are the most common form of ammunition and are generally reusable.  Most modern center fire cartridge cases are made of brass or a brass alloy.  Center fire cartridges can be rimmed as indicated below, or rimless.  The rim is designed to help with extraction of the spent cartridge.  Center fire cartridges can also be belted or non-belted.  Normally, standard cartridges are non-belted and magnum loads use belted cartridgesCenter fire can also be written Center Fire.

Typical Center Fire Cartridge

CENTER FIRE PISTOL FOR INTERNATIONAL COMPETITION: is similar to the pistol used in NRA domestic competition. The trigger pull is three pounds as compared to the NRA requirement of 2 1/2 pounds. Caliber .38 is the normal size used.

CENTER OF MASS: The center of a target.  On human style targets the area in the center of the chest or torso.  Targets should be engaged "Center of Mass" to ensure the best chance of a hit.  Abbreviated COM and pronounced Com.

CETME:  Acronym for Spain's "Centro de Estudios Tecnicos de Materiales Especiales" or in English (Special Materials Technical Studies Center) which was formed in 1948.

CF:  Abbreviation for Center Fire.

CHAMBER: That part of the bore at the breech which is formed to accept and support the loaded cartridge. The rear part of the barrel that is formed to accept the cartridge to be fired. A revolver employs a multi-chambered rotating cylinder separated from the stationary barrel.

CHAMBER, HANDGUN: The chamber of the handgun is located directly behind the rifled portion of the barrel and holds the cartridge during discharge. On pistols, there is a single chamber (an integral portion of the barrel), and the empty casing must be removed and replaced with a new cartridge before another shot can be fired. Depending on the mechanism of action, this process is either done automatically (semi-automatic pistols) or manually (Derringers and some single shot competition style target pistols). In contrast, revolvers contain multiple chambers (that are NOT an integral part of the barrel), located in the cylinder, each holding a single cartridge, which rotate or revolve into the firing position behind a single barrel.

CHAMBER INSERT: A safety device to prevent unauthorized use of a revolver.  Chamber inserts differ from barrel inserts in that they are placed directly into the chamber rather than inserted through the barrel. They are designed to hold the action in an open position.  

CHAMBER THROAT:  Also called THROAT, is that area in the barrel that is directly forward of the chamber and that tapers to bore diameter.

CHAMFER: To ream a taper on the inside of a case mouth.

CHARCOAL COLOR CASEHARDENING:  A method of hardening steel and iron while imparting to it colorful swirls as well as surface figure.   Metal is heated by means of animal charcoal to 800-900° C, then plunged into cold water.

CHARGE: The amount of powder used in the case at each loading. Also refers to the amount of shot used in a shot shell.

CHECKERING: A functional decoration consisting of pointed pyramids cut into the wood or metal, generally applied to the front strap of the pistol grip and to the forend or forearm areas of a rifle stock affording better grip adhesion, handling and control.  Checkering is measured in LPI or lines per inch.   Typical checkering is either 20 or 30 LPI on handguns and rifles.  For information on checkering see the detail box below.

Checkering Patterns & Cutting Tools

Wrap-around or side panel patterns checkering and density of the checkering is typically left to the owners discretion and person preference.  Two kinds of cutters are used namely:

90 degree cutter - the standard side panel checkering is usually cut is 18 or 20 lpi (lines per inch). Seen below is pattern 1 and 2. The wrap-around patterns are cut in 20 or 22 lpi seen in image as 3 to 6.

60 degree cutter - this style allows a higher density lpi and is cut in 22 flat top, 24 or 26 lpi for patterns 3 to 6. Pattern 7 is cut in 26 or 28 lpi. The lpi specified also depends on the quality of the wood selected and density of the grain.

The person in charge of the Range Officers on a shooting range or in a shooting competition.  Abbreviated CRO.

CHOKE:  1. A constriction or narrowing at or near the muzzle end of a shotgun barrel that affects shot dispersion.  2: The constriction in the muzzle end of a shotgun bore by means of which control is exerted upon the shot charge in order to throw its pellets into a definite area or predetermined concentration.  Degree of choke is measured by the approximate percentage of pellets in a shot charge which hit within a 30 inch circle at 40 yards.  For example with a "Full Choke" 65 to 75% of the pellets will hit in a 30 inch circle at 40 yards.  See choke types below.


The narrowing found at the muzzle end of most shotgun barrels is called a choke.  The choke controls the shot pattern and determines at what distance the shotgun will be most effective.  Effectiveness is determined by the approximate number or the percentage of the shot shell pellets that hit in the target area at a specified distance.  Chokes and shot patterns are calibrated by shooting a 30 inch circular target at a distance of 40 yards.  Should you need fewer or less of the pellets in a specified area at other distances simply conduct the test at your desired range.

How a Shotgun Choke works

Just as the nozzle on a garden hose controls the spray of water, the choke of a shotgun barrel controls the spread of the shot.  This shot spread is called the "pattern".  From the tightest to the widest spread, chokes are described as "full", "modified" and "improved cylinder".   A gun that has no choke is called a "cylinder bore".

Full Choke
Tight constriction for dense pattern (approximately 70% of a shell's total pellets in a 30" circle at 40 yards). Best for trap shooting, pass shooting waterfowl, turkey hunting and shooting buckshot loads.

Modified Choke
Less constriction than full choke (approximately 60% of a shell's total pellets in a 30" circle at 40 yards).  Excellent for all-around hunting of waterfowl, long-range flushing upland birds (such as late-season pheasant and sharp tail grouse) as well as other small game.  Also used for trap shooting.

Improved Cylinder Choke
Even less constriction than modified (approximately 50% of a shell's total pellets in a 30" circle at 40 yards).  Ideal for close-in small game shooting, upland bird hunting (such as quail, grouse and pheasant) as well as hunting waterfowl close over decoys.  Rifled slugs also perform very well from this choke.

The following table gives the accepted "shot in circle" percentage obtained with various chokes. 

  Choke Types

Percentage **
Full Choke 65-75%
Improved Modified  Choke 55-65%
Modified Choke 45-55%
Improved Cylinder  Choke 35-45%
Cylinder Bore Choke 25-35%

** Percentage indicates approximate percentage (%) of a shotgun shell's total pellets or shot, that will hit inside a 30 inch circle placed 40 yards from the firing line.

An instrument used to measure the velocity of a projectile.  As velocity is one of the variables in determining bullet performance a chronograph is used to determine the speed or velocity of the projectile. 

CIWS: Acronym for Close-in-Weapons-System.  Pronounced [ `Sea Whiz ].

CLASS 2 SOT: Firearms manufacturers Special Occupational Tax or "Special Occupational Taxpayer). Specifically the Class 2 SOT is the type of Special Occupational Tax paid by firearms manufacturers and those who make NFA (National Firearms Act) items including sound suppressors and machine guns. Holders / payers of the Class 2 SOT can make or manufacturer machine guns, silencers, suppressors, short rifles, short shotguns and AOW (Any Other Weapon) with out paying a tax for each item made. A Class 2 SOT can have weapons transferred to them tax free, from other SOT's. They must have also have a type 07 or type 10 Federal Firearms License or FFL. Class 2 SOT's do not need to ask prior permission of BATF to make a weapon. They are required to notify BATF of the making / manufacturing of a firearm or NFA item within 24 hours of it manufacturer by filing BATF Form 2 with the ATF. For more information on NFA Weapons - Machine Guns -Silencers and SOT categories, please see the NFA FAQ.

CLASS 2 MANUFACTURER: Term used to describe a Class 2 SOT (Special Occupational Taxpayer). Also called a Class 2 Dealer.  See Class 2 SOT Above. A Class 2 SOT costs $1000 a year, or $500 per year for a small manufacturer who does less than $500,000 in gross receipts in their manufacturing business. One must also have the appropriate FFL (Federal Firearms License)  to engage in the specific firearms manufacturing activity. This is because most NFA weapons are also title 1 weapons, and thus fall under both the law regulating Title 1 Firearms, the Gun Control Act or GCA and for Title 2 (Class 3) Firearms, the National Firearms Act of 1934 or NFA-34, so both separate regulation must be complied with. As with the privacy of SOT Registry information and transfer information, SOT status is protected tax information, and ATF can not release lists of SOT holders, as they can with FFL holders. 



CLASS 3 SOT: A Class 3 SOT costs $500 a year, due each July 1. 

CLASSIC SAFETY POSITION:  A traditional rifle safety where the safety has only two (2) positions, Safe and Fire, without the Loading position found on many fine arms and modern rifle safety systems.  Classic or Classical Safeties typically do not incorporate a separate firing pin safety or firing pin disconnect system.  The "Safe Loading" position is the middle position and allows the shooter to work the action and open the bolt while the trigger is in "Safe" and deactivated.

CLICKS: Term used for adjustment increment on an optical scope.  The amount of change is measured by "clicks" turned.  Typical Optical Rifle Scopes move 1/4 MOA ( Minute of Angle ) per click, but some adjust to 1/8 MOA and others like ACOG's as specified in the users manual.

CLOSE-IN-WEAPONS-SYSTEM (CIWS): Weapons system employed on military surface ships that typically includes a fire direction radar and a high speed, high rate of fire Gatling style gun.  The CIWS (Pronounced `See-wiz) is used as a close in, last line of defense anti-missiles defensive system that fires a hail of projectiles at incoming anti-ship missiles (ASM).  Most American Navy surface combatants use the Phalanx System with an automated  20 millimeter multi-barreled cannon, similar to the Vulcan.  On some Main Battle Tanks (MBT's) a CIWS is employed that launches small strips of diffusing material, similar to aluminum foil, used to confuse or blind targeting radar and anti-tank guided missiles (ATGM's).

CLIP: A device for holding a group of cartridges.  Typically a Clip is used to charge, load or feed the Magazine.  The terms "Clip and Magazine" are NOT interchangeable in strict technical usage, however semantic wars have been fought over the word, with some insisting it is not a synonym for "magazine."  Like it or not, right or wrong, for 80 years the term CLIP has been used by many gun manufacturers and the USMC. The rest of the military services use the term magazine. There is no argument that it can also mean a separate device for holding and transferring a group of cartridges to a fixed or detachable magazine or as a device inserted with cartridges into the mechanism of a firearm becoming, in effect, part of that mechanism.  However real "Gun Folk" cringe at the miss use of the term Clip for Magazine.   See Clip definition 2 below. 

CLIP 2: A device used to rapidly load a magazine.  "Clip" is often used to refer to a magazine, but this is an improper use of the term.  There are two kinds of clips:  Stripper clips and en bloc clips:  

  • Stripper clips hold 5 to 10 rounds of ammunition by their bases.   To load the magazine, the clip is placed in a guide which is either a part of the gun, or a separate guide which slips onto the magazine.  Weapons which may be loaded from stripper clips include the Lee-Enfield series of rifles, Mosin-Nagant Rifles, the M1903 Springfield, and the Mauser 1898.  The Steyr-Hahn M1911 and Mauser "Broom Handle" semiautomatic pistols also use stripper clips.  Stripper clips are also called "chargers."

  • En bloc clips hold the cartridges together by their bases and their bodies; the clip and the rounds are inserted into the magazine as a unit.  When the last round is loaded, the clip is automatically ejected from the magazine.  Weapons loaded with en bloc clips include the Steyr-Mannlicher straight pull bolt action, the Mannlicher-Carcano rifles, and the US M1 Garand.  (In the M1, the clip is ejected up after the last round is fired.)

COCK: To ready the mechanism of a gun for firing, as in "to cock the hammer."  Was noun used to name the hammer in former times, as the hammer of an old matchlock rifle looked like a cock (or a male chickens) head.

COCKING INDICATOR: Any device which the act of cocking a gun moves into a position where it may be seen or felt in order to notify the shooter that the gun is cocked.  Typical examples are the pins found on some high-grade hammerless shotguns which protrude slightly when they are cocked, and also the exposed cocking knobs on bolt-action rifles.  Exposed hammers found on some rifles and pistols are also considered cocking indicators.

COF:  Abbreviation for Course of Fire.

COLD RANGE:  1. A range that does not allow shooters to carry loaded weapons away from the firing line.  For safety and liability reasons, this is the usual practice. The vast majority of ranges in the US are cold ranges.  2.  When the no one is touching their weapon (and no weapons are loaded) and people may be downrange, there is a cold range.   At events, declaring the range "cold" or "hot" is at the discretion of the range officer (RO).  Once the RO has called the range hot, no one should pass the firing line.  The range is declared "Cold" after all firearms are cleared to allow target pasting and administration of the range and targets.

COLOR CASE HARDENING:  A method of hardening steel and iron while imparting colorful swirls as well as surfaces figure.  Normally, the desired metal parts are put in a crucible packed with a mixture of charcoal and finely ground animal bone to temperatures in the 800 degree C - 900 degree C range, after which they are slowly cooled, and then submerged into cold water.

COLT, SAMUEL: Lived 1814-62, American inventor; born in Hartford, Conn. His revolving breech pistol (patented 1835-36) was one of the standard small arms of the world in the last half of the 19th century.  Colt also invented a submarine battery used in harbor defense and a submarine telegraph cable. There is a famous saying that goes "God created man... Sam Colt made them equal".

Samuel Colt
Great American Inventor & Gun Maker

Samuel Colt

Samuel Colt was born in Eighteen Fourteen (1814) and died in Eighteen Sixty-two (1862). He only lived to be Forty-Seven but his impact on firearms, military weapons and warfare is still present even in today's world, years after his time.  Sam Colt shaped the way the nation fought its wars and the way individuals protected themselves,  with his invention of a firearm capable of firing multiple times without reloading.  The world would not be the same place without him.

Samuel Colt was born in Hartford Connecticut; he had the inventor's charm even as a child. He was sent to boarding school after he conducted a demonstration with an explosive mine that showered mud and debris all over the school.  Then, at the boarding school, Amherst Academy, another fire related incident caused the school to catch on fire, resulting in extensive damage.  The young Sam Colt was then again expelled from school. 

Colt's Wooden Revolver

Samuel Colt was sent into a sailors apprenticeship in 1830, at the age 16.  He was on a voyage to India on the ship Corvo, when he noticed certain characteristics about the workings of the ships wheel.   The ship's wheel was always locked in place with a clutch mechanism, no matter how far it was turned.  With his creative mind, he thought that the same principal could be applied to a firearm.  Colt then carved a wooden model of this now famous revolving firearm.

This wooden model was the first Colt ever made.  In Eighteen Thirty-five (1835) Colt perfected the Colt Revolver and in Eighteen Thirty-six (1836) he received a patent.  This firearm had a revolving cylinder with room for five to six bullets.  It was operated by cocking the hammer which turned the cylinder.  When the cylinder turned it aligned an ammunition cartridge with the barrel.  The trigger was pulled and the gun fired a single shot.  Pulling the trigger released the hammer which had a striking mechanism that hit the primer of the cartridge.  By again cocking or pulling the hammer to the rear, the process was repeated until the cylinder was empty.  In the same year, Colt produced 3 new revolvers and two rifles.  

The Colt revolver models were: The pocket and the belt and holster. The two rifles had the same mechanism as the pistols with revolving cylinders. In 1839 Colt mad a carbine rifle. Colt continued making the guns, but in a time of peace, there was not a high demand for his products.  With all the models he had made the orders never exceeded 100. So Colts company, Colt's Patent Arms Manufacturing Company, went bankrupt in 1842.  Without his business to run he devoted his time to creating electrically discharged underwater explosives and mines to sell to the government.  He also worked on waterproof ammunition for military and hunting application.  In association with Samuel Morse, he created the telegraph line. 

During 1845, Texas Rangers engaged in battle with hostile Indians.  The Colt revolvers they were using at the time proved very effective in defeating the Indians.  Their combat  effectiveness was greatly enhanced because of their rapid-fire capability, and the ability to quickly reload the cylinder.  The U.S. War Department was impressed and ordered several Colt Revolvers.  In 1846 the Mexican American War began.  Colt worked with U.S. Army Captain Samuel H. Walker on the development of a more powerful revolver.  An order for 1000 of his, new more powerful, rapid firing revolvers was placed by the U.S. Ordinance Department.

Early Colt Revolvers

Patterson Colt Revolver

Colt Legend Revolver

These new revolvers where called the "Walker Colt".   Samuel Colt was producing firearms and making money, but he did not have his own factory.  He got in touch with Eli Whitney Jr., son of Eli Whitney, the inventor of the cotton gin.  The order was sent out in 1847. He then began to build his own factory.  In 1851, he made leaps that would eventually do nothing but help his business. 

Sam Colt was the first American manufacturer to build a plant in England.  He also purchased 250 acres of land called the South Meadows.  This land was constantly flooded and sold for a low price.  Colt built a two mile long dike and he then built a factory that was protected from the rivers waters. This factory was on the cutting edge of manufacturing technology. The factory put out 5000 handguns in the first year of operation. 

Then Colt, with his new machinery focused on interchangeable parts. Eighty percent of those parts came from the state of the art machinery. These were the top of the line manufacturing machines available in the world.  The precision parts in the colt revolvers were made by this machinery. Samuel Colt was proud of this when he said " There is nothing that can't be produced my the machine." 

In 1855 Colt founded the firm" Colt's Patent Fire Arms Mfg. Co.". It was founded in Connecticut with 10,000 shares of stock.  Colt claimed 9,996 shares. He gave one share to each of his businesses associates.  In 1856 the company was producing 150 guns a day.  The Colt firearm's reputation of exceptional quality quickly spread throughout the world.  This made Samuel Colt one of the top ten wealthiest businessmen in the U.S.  More firearms were needed; Colt expanded his engraving department.  He was a great fan of engraving and gold inlay on his firearms and thought it would be a good idea to make it more available to the public. 

Colt created show guns that were beautifully engraved with lots of gold inlay. His guns won prizes at world trade fairs, constantly.  Colt's company sold firearms through traveling salesmen. They were actually wholesalers that sold large quantities of guns to resellers and shop keepers.  They also took orders from the rich and famous, these orders were taken directly to the factory.  Samuel Colt was soon recognized for being one of the earliest American manufactures to realize the effectiveness of marketing. 

Sam Colt built his house, Armsmear; it was one of the greatest houses ever built.  In 1860, Sam Colts health began to fail. The country was heading towards civil war. Before war was declared, Colt shipped his products to the southern states. As soon as war broke out, Colt stopped shipment to the C.S.A. and was supplying firearms exclusively to the Union. The Colt Armory was producing a huge amount of weapons, and was running at full capacity. Colt was making $250,000 dollars a year by 1861. 

Samuel Colt died January 10, 1862. He was only 47. He was worth $15 million dollars. Which today equals about $300 million dollars. In his life he produced over 400,000 firearms. The company was then under the control of his immediate family until 1901. 

  Abbreviation for Center of Mass.  Usage would be "She got a good COM hit" or "One should aim for COM on all targets."

COMB: The portion of the rifle or shotgun stock on which the shooter's cheek rests.

COMBAT SIGHTS:  Sights suitable for combat.  Term usually refers to Notch and Post style sights and night sights and excludes large optical sights and scopes.  Combat sights are easy to acquire, line up on the target and use quickly in an emergent situation.  The best combat sights are nights sights with tritium inserts.  85% of the defensive uses of a firearm occur at night or in low light conditions.  I consider another important variable of effective combat sights to be a sufficient size and of a design that facilitates the ability to use the rear sight body to rack the slide on an automatic pistol.  In may emergency situations you may have to rack the slide with only one hand.  If the rear sight are suitable for combat you can use the rear sight to rack the slide.  You may be wounded or your other hand may be holding a flash light or the assailant.

COMBAT SHOOTING: A generic reference to a shooting sport (generally using handguns) that seeks to simulate the use of small arms as an instrument of personal protection in a tactical or combat scenario.   Depending on the particular type of match, the rules and equipment used it may or may not provide a realistic simulation.  It is often used for training purposes.  In real armed military combat, handguns are rarely used.

COMBINATION GUN:  Generally a break open shotgun configuration fitted with at least one shotgun barrel and one rifle barrel.  Such guns may be encountered with either two or three barrels, and less frequently with as many as four or five, and have been known to chamber for as many as four different calibers.

COMPENSATED:   Refers to a gun with a compensator, or more specifically a barrel, that has vent holes to allow gas to escape.  Since the holes are drilled on the upper side of the barrel the escaping gas pushes the gun downward. This downward action compensates for the muzzle flip that tends to occur when a gun is fired.

COMPENSATOR: A recoil-reducing device which mounts on the muzzle of a gun to deflect part of the powder gases up and rearward.   Also called a "muzzle brake" or "comp" as in a comp gun.

COMPRESSED CHARGE:  A charge of powder which so nearly fills the case that it is compressed when the bullet is seated.

COMPRESSED CHARGE: A charge of powder which so nearly fills the case that it is compressed when the bullet is seated.  Compressed charges can increase the muzzle velocity of certain loads, but there is a point of diminishing returns as all of the powder may not be able to burn in the specified load.  Hand loads are not as simple as increase the powder, increase the speed of the bullet.  Compressed Charges can result in very high and often dangerous chamber pressure.  Please consult your reloading guide and load safely.

COMPONENTS: Any of the various parts which go into the making of a cartridge.  Also the parts used to make up a firearm.

CONCEALED CARRY PERMIT (LICENSE): A permit to "Carry a Concealed Weapon" or CCW.  In some states also called CCL.  A permit or license issued by a designated authority (a state, county, or city official) authorizing a citizen to carry a concealed weapon.   CCW laws vary greatly from state to state.  In some states practices regarding the issuance and enforcement varies greatly between different cities and counties.  Also refereed to as a CCW or CCL.  See below for details.

Concealed Carry License and Permits

31 states now have Right To Carry laws, respecting the fundamental individual right of self-defense by allowing people to carry firearms for protection against criminals. 127 million Americans, nearly half the U.S. population, including 60% of handgun owners, live in Right To Carry states.

Right To Carry Map

With over 20,000 "gun control" laws on the books in America, there are two challenges facing every gun owner.  First, you owe it to yourself to become familiar with the federal laws on gun ownership.  Only by knowing the laws can you avoid innocently breaking one.

Second, while federal legislation receives much more media attention, state legislatures and city councils make many more decisions regarding your right to own and carry firearms.  NRA members and all gun owners must take extra care to be aware of anti-gun laws and ordinances at the state and local levels.

In general, states fall into one of the following categories:

No Permit Required: Civilians may carry a concealed weapon without applying for any special permit. (There may still be restrictions on who can carry and when or where guns may be carried.)

Right to Carry / Shall Issue: There is a permit process, usually requiring a fee, a background check, and training.  However, a permit will be issued when the requirements of the permit process are met.  In a "Shall Issue" state it is up to the state to prove you are not qualified to have a CCW/CCL.  Currently more than 30 of the states in America are in this category, they are shown in blue above.

Limited Issue / May Issue: There is a permit process, usually requiring a fee, a background check, and training. However, a permit will be issued only when the issuing authority determines that there is good cause.  Local officials often have very different interpretations regarding when permits should be issued in such states.  California and the 12 states shown in yellow above are currently in this category.

Non Issue / Don’t Issue: States that do not offer CCW' s under any circumstances.  The 7 states shown in red above are in this category. Some of these states have "Open Carry" provisions.

Concealed Carry Terms & Abbreviations:

CCL: Concealed Carry License.

CCH: Concealed Carry Holster.

CCI: Concealed Carry Instructor / Instruction.

CCT: Concealed Carry Training / Trainer.

CCW: Concealed Carry Weapon, as in CCW Permit.

CCP: Concealed Carry Paddle (Paddle style holster).

RTC: Right-to-Carry, same as "shall issue" or have provisions for a less restrictive and discretionary permit system.

NICS: National Instant Check System.  Background check system implemented in November 1998 and used in 24 states for all gun purchases and in 11 additional states for handgun purchases.  [States that had in place or implemented an equal to, or more stringent background check system are  exempt from the Federal system or "NICS". ]

NRA: National Rifle Association.

NRA-ILA : National Rifle Association (NRA) Institute for Legislative Action.

Reciprocity: Term defining laws that allow any person with a valid firearm carrying permit or license, issued by a state, to carry a firearm in another state.  Many states currently have reciprocity for states that have similar standards of issue and licensing.  in states that issue firearm carry permits, each state's laws governing where firearms may be carried would apply within its own borders.  Federal legislation is pending that would allow National Reciprocity.

For specific information regarding your states firearm laws contact your local Sheriff or NRA Affiliated Gun Club.  An online listing is also available from the NRA-ILA web: Click Here and then click on Firearms Laws on the right hand column.

Information Courtesy of:
NRA Institute for Legislative Action
11250 Waples Mill Road
Fairfax, Virginia 22030

Additional information on everything Concealed Carry is online at URL:

  Term used to define the 5 different readiness states or "Cary Methods" when using a classic 1911-pattern single action automatic pistol.  A detailed explanation and the advantages and disadvantages of the conditions are listed in the table below.

Readiness Conditions
- The Five Conditions of Readiness -

Mr. Jeff Cooper, the so called guru of the 1911, originated and popularized the "Condition" system to define the state of readiness of the 1911-pattern semi-automatic pistol. 

The 5 Conditions are:

Condition 0 - A round is in the chamber, hammer is cocked, and the safety is off.

Condition 1 - Also known as "cocked and locked," means a round is in the chamber, the hammer is cocked, and the manual thumb safety on the side of the frame is applied.

Condition 2 - A round is in the chamber and the hammer is down.

Condition 3 - The chamber is empty and hammer is down with a charged magazine in the gun.

Condition 4 - The chamber is empty, hammer is down and no magazine is in the gun.

Condition Zero should only be used when one is ready to engage targets or fire the pistol.  Many 1911-patern pistol will fire if dropped or if the hammer is hit or rubbed in Condition Zero.

Condition One is the mode of readiness preferred and recommended by the "experts". Generally speaking, Condition One offers the best balance of readiness and safety. Its biggest drawback is that it looks scary to people who don't understand the operation and safety features of the Single Action Semi-Automatic pistol. Decocking this type of handgun is still a dangerous practice and many of the so-called experts have been in condition one only to look down and notice that the manual safety was inadvertently disengaged making the gun in Condition Zero. There are thousands of police reports, including many involving police officers, where the shooter/victim dropped the hammer on a loaded chamber in an attempt to "safe" their M-1911 style pistol and "accidentally" discharged a flaming hot .45 ACP round into themselves or a innocent by-stander. 

Condition Two is problematic for several reasons, and is the source of more negligent discharges than the other conditions. When you rack the slide to chamber a round in the 1911, the hammer is cocked and the manual safety is off. There is no way to avoid this with the 1911 design. In order to lower the hammer, the trigger must be pulled and the hammer lowered slowly with the thumb onto the firing pin, the end of which is only a few millimeters away from the primer of a live round. Should the thumb slip, the hammer would drop and fire the gun. Not only would a round be launched in circumstances which would be at best embarrassing and possibly tragic, but also the thumb would be behind the slide as it cycled, resulting in serious injury to the hand. A second problem with this condition is that the true 1911A1 does not have a firing pin block and an impact on the hammer which is resting on the firing pin could conceivably cause the gun to fire, although actual instances of this are virtually nonexistent. Finally, in order to fire the gun, the hammer must be manually cocked, again with the thumb. In an emergency situation, this adds another opportunity for something to go wrong and slows the acquisition of the sight picture.

Condition Three adds a degree of "insurance" against an accidental discharge since there is no round in the chamber. To bring the gun into action from the holster, the pistol must be drawn and the slide racked as the pistol is brought to bear on the target. This draw is usually called "the Israeli draw" since it is taught by Israeli security and defense forces. Some of the real expert trainers can do an Israeli draw faster than most of us can do a simple draw, but for most of us, the Israeli draw adds a degree of complexity, an extra step, and an opening for mistakes in the process of getting the front sight onto the target.

In my simple mind all of these safe carry and employment problems along with low magazine capacity and other problems that are typical of the 19911-patern pistol is why most armed professionals and our military have transitioned to modern,  traditional double action / single action (DA/SA) automatic pistols like those made by SIG-Sauer, Beretta and Glock.  There is still a zealous and very vocal group of 1911 shooters and supporters.  I jokingly refer to them as "The Cult of Colt". To the 911 Cult, criticizing their beloved 1911 is akin to talking about their mothers or quashing their most deeply held religious beliefs. I remind them (often) that "one can not make up for a small brain with a big bullet."

The slope of the forward end of the chamber of a shotgun which decreases the chamber diameter to bore diameter. Also called a forcing cone.

COP KILLER BULLET: A non-technical term used to describe politically unpopular defensive ammunition.  The term "Cop Killer Bullet" is an inflammatory phrase having neither historical basis or a legal or technically defined meaning.  For the record, any bullet is capable of killing a police officer or any other human being.  The term was used by anti-gun proponents in the late 1980's and early 1990's to vilify and then restrict certain types of politically unpopular ammunition.  The ammunition in question was in fact a defensive round with an effective hollow point bullet very similar to ammunition that has  been commercially available for over 40 years.  The anti-gun lobby stated falsely that the Cop Killer Bullets were capable of defeating or penetrating body armor or so called "bullet proof vests" which was untrue.  In fact the so called "Cop Killer Bullets" were renamed and repackaged and are still commercially available today.  If anything all the political hoopla only served to make them more popular and more common.

COPPER FOULING: The partial obstruction and loss of accuracy caused by accumulated metal residue in the barrel of a gun.  Copper fouling is the same as leading or lead fouling, but is caused from the copper covering on copper jacketed bullets.  The fouling occurs when the metal particles fill in the grooves of a rifled barrel, which make the rifle shoot more like a smooth bore.  Accuracy is lost because the fouled riffling is not imparting adequate spin and stability on the projectile.  Several chemicals are available to remove both lead and copper from the barrel of a gun.

CORDITE:  A chemical used as propellant.  Smokeless powder composed of nitroglycerin, guncotton, and a petroleum substance usually gelatinized by addition of acetone and pressed into cords resembling brown twine.

CORTO: Italian for "short."  Seen as part of a cartridge designation.  E.g., 9mm Corto, which is the same as the .380 ACP or the German 9mm Kurz.

CORROSION: The eating away of the bore by rust or chemical action.

COURSE OF FIRE:  A term used to describe a stage in competitive shooting matches.  A course of fire or COF may involve some set of standard exercises or may involve a scenario designed to simulate a real world situation.  The description of the COF would describe all the targets relative position on the course and the shooters actions at each target.  It also specifies and safety precautions or restrictions applicable in that stage of competition.  A course of fire can be made up of one or more strings.

CRANE:  In a modern solid-frame, swing out revolver, the U-shaped yoke on which the cylinder rotates, and which holds the cylinder in the frame.

CREEDMOOR:  Famous rifle range on Long Island New York established by the fledgling National Rifle Association in 1873 with appropriations from the New York Legislature. The name is synonymous with long range shooting competition using black powder rifles. Competitions at Creedmoor gave birth to marksmanship as an amusement and to shooting as a sport without military implications in the United States. Creedmoor Matches were the forerunner of the Palma Matches held today. For more information read "The Story of Creedmoor" written by David Minshall in the detail box below.

The Story of Creedmoor
by David Minshall

Original Published by: Long Range Muzzle Loader - Used with permission.

"At the close of the Franco-Prussian war of 1870-71, the American rifle movement took its rise in a series of articles, written for the only military paper of the country, by a militia officer. They appeared in the "Army and Navy Journal," and were written by Mr. George W. Wingate, a young lawyer of New York City. The history of the movement from the time when Wingate first published his articles to the time of the triumphs of Creedmoor and Dollymount is one of persistent effort against universal apathy. The only class that encouraged the attempt at first was the citizen soldiery of a single city, and even their support was by no means general. The first meeting for the formation of a rifle club was abortive, from the lack of sufficient numbers to constitute a legal quorum, and it was only on a second attempt that the club was formed. The first President of the "National Rifle Association," as it was called, was General Ambrose E. Burnside, who made a very good figure-head, but under whose leadership nothing was accomplished. It was not till the second year of its existence that any real progress was made. Then, by the efforts of the new President, Colonel Church of the "Army and Navy Journal," and the Secretary, Mr. George W. Wingate, the New York Legislature of 1872 was induced to appropriate $25,000 for the purchase of a range near New York city, the Association agreeing to raise $5,000 on its part." [The Story of Creedmoor, Frederick Whittaker, 1876]

Much effort went in to the search for a suitable site for the new range in the vicinity of New York to no avail. Finally the search turned to the plains of Long Island. Here the NRA bought a 70 acre site, at one time owned by a farmer named Creed. Colonel Henry G. Shaw, a member of the NRA range committee, is credited with coining the word "Creed-moor" having observed the similarities of the site with the moorland of Great Britain.

Creedmoor was opened in the spring of 1873 and was almost exclusively used by National Guardsmen, with shooting mostly at short range. The public interest in Creedmoor was slight, and the shooting poor when compared with that of the Volunteers in Great Britain. Contests and rifles there during 1873 were almost exclusively military, confined to members of the militia or men shooting with their rifles. The few "any rifle" competitions were offhand at 200 yards. The first season, however, witnessed the formation of a small club of enthusiasts, an offshoot of the parent association. George W. Wingate, with a few others, organized the "Amateur Club" of New York City. This club was designed to cultivate the use of the sporting rifle, and to develop marksmanship as an amusement, with no ulterior military purpose. This being the case, the Amateur Club speedily became a thriving institution, and many men joined it who would never have been caught in a militia regiment.

A challenge addressed to American riflemen in the winter of 1873 resulted in a match that brought the American rifle movement to the attention of the public. Since 1862 England and Scotland had been competing at Wimbledon for the Elcho Shield, the match comprising teams of eight, each man firing fifteen shots at 800, 900 and 1000 yards. In 1865 Ireland was first permitted to enter the match, and in 1873 took the Elcho Shield for the first time. Elated with their success, the Irish marksmen, issued a challenge to American riflemen to decide the 'championship of the world.' The Irish would all use Rigby muzzle-loaders and the Americans be required to use arms of US manufacture. The Amateur Club on behalf of the riflemen of America accepted this challenge.

Despite the invitation for riflemen to contest for places in the American team being published in daily papers over the United States, response was scanty. In the end it became clear that the Amateur Club would have to fight single-handed. The final team of six, three using Remington and three using Sharps breechloaders began to practice in earnest. They monitored their progress by calculating average scores for the Elcho Shield winners, and comparing their own.

The eventful day arrived, and on 26 September 1874 Creedmoor witnessed a crowd of over five thousand people all come to see the grand match. At 800 yards the Americans had a good lead. The Irish gained on them at 900 yards, and by the time they had finished shooting at 1000 yards were ahead of the Americans. In the end the match was to be determined by the very last shot fired by the Americans. Shooting a bull's eye at 1000 yards to score 4, the Americans emerged the winners on 934 points to the Irish team's 931.

This match was the forerunner the Palma Match and a series of international competitions held through the 1870's and 1880's. Public interest eventually waned and the matches went into decline, until in 1890 Creedmoor was deeded back to the state of New York and the NRA became dormant. Activities were not revived again until 1900, and in 1901 the Palma Trophy was again shot for. The event continues to this day.

Original Published by - Long Range Muzzle Loader - http://www.LRML.Org

Copyright © 2001 David Minshall - All Rights Reserved.

 - Used with express written permission -

Style of rifle used at "Creedmoor" international shooting matches and in other "Long Range" shooting competitions. The first 'Creedmoor' rifles were manufactured by Sharps and Remington for the Irish / American international rifle match of 1874.  Creedmoor was not a brand name or a rifle manufacturer, but was commonly used as the model or style with a model number such as "Sharps Model 1877 Creedmoor". Creedmoor style rifles are often built on the Sharps 1877 pattern rifles and on similar muzzle loading black powder long guns, though the American team used Sharps Model 1874 guns in their first international competition at Creedmoor. Now the name is synonymous with very high quality long range rifles and has even been applied to guns made before Creedmoor matches. The rifle used in the film "Quigley Down Under" was a "Creedmoor" style rifle. Manufacturers still make "Creedmoor" model rifles today. Creedmoor models are still used in long range black powder competitions and I would add, they are still winning, even though it has been over 125 years since the international competitions at the Long Island range.

The 1877 Sharps "Creedmoor" Rifle

By the year 1875, Long Range Target shooting was very much in vogue in America. The Creedmoor Rifle Range was established on Long Island, New York, and the competition between the rifle companies to produce accurate Long Range Target rifles was fierce. The Sharps Rifle Company's Model 1874 had already proven itself a winner in the 1875 match against the Irish team at their Dollymount range. 

As competition grew, so did the demand for accuracy. Shooters from all over the country wrote the Sharps Rifle Company suggesting their ideas for improvement. The most constant request was for a smoother, faster action and a heavier more stable barrel. The Sharps Rifle Company listened to the requests and the result was the Model 1877. With it's English lock, improved lock time, and it's Rigby style barrel to reduce "barrel whip"; the Sharps Rifle Company, once again, had a proven winner.

Creedmoor tang sights are fully adjustable for windage and elevation. The long Creedmoor sight was designed for heavy target rifles like the Rolling Block. The short Creedmoor sight is suitable for lever actions and small single shot target rifles. The Deluxe Creedmoor sight is precision, match grade version of the long Creedmoor model.

CREEDMOOR SPORTS INC.: Manufacturer and retailer of fine quality shooting products and supplies for shooting competition and the tactical shooter. This is a top notch outfit with the very best of reputations among competition shooters (who are typically very anal and demanding). Creedmoor Sports has been manufacturing top quality products for the competitive rifle shooter and tactical sniper since 1979. That almost 25-years. All products manufactured by Creedmoor Sports, Inc. are made in the USA and handcrafted in Oceanside, California by a production staff that averages over 10 years of service with the company. All products manufactured by Creedmoor come with a Lifetime Warranty against manufacturers defect, yes LIFETIME.

Web URL:

Tel: 1-800-CREEDMOOR (1-800-273-3366)

E-mail: [email protected]

Creedmoor Sports, Inc.
P.O. Box 1040
Oceanside, CA 92051

CRIMP: The bending inward of the case mouth to grip the bullet. With shot shells the term applies to the closure at the case mouth.

CRIMPED PRIMER: A forcing inward of the brass around the top of the primer pocket. This is frequently found on military cartridges and is done to prevent set-back of primers.  The crimp must be removed before repriming the case.

CRO:  Abbreviation for Chief Range Officer.

CROSS-DOMINANT:  In reference to the shooters eye dominance, to be cross-dominant means that you are right-handed, and yet rely on your left eye to aim, or vice versa.  It is more common to be left-handed and left-eyed, or right-handed and right-eyed, but it is not unheard of to be cross dominant as well.  Switching eye dominance is no simpler than switching hand dominance; if your brain is wired to rely on your right eye, there is little you can do to change this.  Some people try to force this, but it is unnecessary.  I am Cross-Dominant as are several of my shooting buddies including a world class SF Sniper, an IPSC Grand Master and a few normal humans who happen to be excellent shots.

CROSSFIRE:  A shot accidentally fired on a target assigned to another shooter.  In tactical terms being in an impact area between fires or being in a position between two points of fire.

CROSSHAIR:  Either of two fine strands of wire crossed in the focus of the eyepiece of an optical instrument or scope and used as a calibration or sighting reference.  Both Cross Hair & Crosshair are correct.

CROSS HAIR:  Term for the crossing wires or other aiming mark in an optical sight.  The fine wires or material look like fine hair lending to the term, however during World War II, a bombing sight was developed using real human hair.  It was called the Norton Bomb Sight and all of the Cross-Hairs in the bombing apertures used the hair from one American woman who volunteered and was selected for the properties of her hair.  See also the detailed definitions for Reticule & Graticule.

CROWN:  The recessed end or countersunk bore of a muzzle.  Done to insure that the mouth of the bore is square with the bore axis and that the edge is countersunk below the surface to protect it from impact damage.

CROWNING: The rounding or chamfering normally done to a barrel muzzle to insure that the mouth of the bore is square with the bore axis and that the edge is countersunk below the surface to protect it from impact damage. Traditionally, crowning was accomplished by spinning an abrasive coated brass ball against the muzzle while moving it in a figure eight pattern until the abrasive had cut away any irregularities and produced a uniform and square mouth.  Typical crown angles are 8 to 14 degrees, with the 11 degree crown angle being most common.

CRUFFLER:  Noun.  Originally the holder of a Type 03 (C&R) FFL, but now anyone who has an interest in old, historical, or just plain weird firearms for which ammunition is usually hard to come by.

CRUFFLE:  Verb.  To seek out old, historical, and weird firearms to shoot, study, admire, and place in historical context.  Includes engaging in ceaseless research, correspondence, and conversation about same.  Also requires a refinement of fiscal priorities i.e. "I can eat this week, or I can get that all-matching Norwegian .30-06 conversion K98k".

CRUFFLING:  Active Participant in the art of finding Curious & Relics.  For a true Cruffler, this is often equated with breathing.

CRYO: Slang for Cryogenic as in Cryogenic Tempering or Cryogenic Treatment.  Usage "My AR-15 has a "Cryo" barrel.  See detailed descriptions below.

CRYOGENICS: The word Cryogenics is derived from two Greek words.  Cryo or "kryos", which means cold,  and genics or "genes", which means the science of or the study of.  Cryogenics is part of a very broad area of science, covering food preservation, medical treatment, thermal imaging, industrial gases and liquids.  Please see the details of Cryogenic Tempering below for information on how Cryogenics relate to firearms and gunnery.

CRYOGENIC TEMPERING:  Computer controlled cooling process that relieves barrel stress by subjecting the barrel to a temperature of - 300 degrees F for 22 hours.  Also know as Cryo Treatment.  Our test have proved that a properly cryogenically treated rifle barrel will not only shoot 15 to 50% tighter groups, but will also be easier to clean and most importantly will have 200 to 300% better durability.  See below for a detailed explanation and for contact information on a state of the art cryogenic treatment provider.

Cryogenics - by Advanced Cryogenics

"About Cryogenics"

The word Cryogenics is derived from two Greek words. Cryo or "kryos", which means cold and genics or "genes", which means the science or study of.  Cryogenics is part of a very broad area of science, covering food preservation, medical treatment, thermal imaging, industrial gases and liquids.  At Advanced Cryogenics, we specialize in a sector of Cryogenics known as Deep Cryogenic Tempering.

Deep Cryogenic Tempering

It is called Deep Cryogenic Tempering, because we operate at temperatures from -240 degrees Fahrenheit to -320 degrees Fahrenheit. Shallow Cryogenics, would be the process of cooling to temperature from -110 degrees Fahrenheit to -239 degrees Fahrenheit.

Deep Cryogenic Tempering is the process of cooling (using liquid nitrogen) inert materials ( primarily metals ) at a controlled rate until the material reaches -300 degrees Fahrenheit. These parts are then maintained at -300 degreed Fahrenheit for a pre-determined time period.  After which they are return to ambient temperature. But, this is not the end. The materials are then subsequently tempering in a series of heating cycles.

Cryogenics - The Science of Cold

Cryogenics is the science of ultra low temperatures and the study of its effect on various materials.  The upper limit of cryogenic temperatures has not been agreed on, nut the National Bureau of Standards has suggested that the term cryogenics be applied to all temperatures below -150 degrees C ( -238 degrees Fahrenheit or 123 degrees above absolute zero on the Kelvin scale ).   Some scientists regard the normal Boiling point of oxygen ( -183 degrees C or -297 degrees Fahrenheit ), as the upper limit. 

Cryogenic Temperatures, Cryogenic temperatures are achieved either by the rapid evaporation of volatile liquids or by the expansion of gases confined initially at pressures of 150 to 200 atmospheres.  The expansion may be simple, that is, through a valve to a region of lower pressure, or it may occur in the cylinder of a reciprocation engine, with the gas driving the piston of the engine.  The second method is more efficient but is also more difficult to apply.

Information Courtesy of
Advanced Cryogenics

5659 Commerce Drive 
Suite 101
Orlando, FL 32839

Tel: 1-877-663-2796 

On the Web At URL:

Abbreviation for Classical or Classic Safety Position.

CUP or C.U.P.:  Abbreviation for Copper Unit of Pressure.  A pressure value determined by means of copper "crushing" cylinders using SAAMI recommended procedures and equipment.  The amount of crushing caused or the measured change in the mass of a standardized copper cylinder when exposed to the explosive force of a certain charge determines the CUP value.  The CUP measurement is used to express chamber pressure or the pressure the expanding gasses exert on the interior parts of a firearm.  CUP measurements replaced the L.U.P. or Lead Unit of Pressure  measurement of old.  CUP & LUP are now generally obsolete being replaced by Piezo electric measurements of actual pressure, but CUP values are still referred to for comparison.

CUPRO-NICKEL: An silver-colored alloy of copper and nickel used to make bullet jackets. U.S. Ball, .30 caliber, M1906, and British .303 Small Arms Ammunition Ball MK. VII, for example, were made with cupro-nickel jackets.

CURIOS & RELICS: a.k.a. Curios or Relics; Any firearm that was demonstrably manufactured 50 years or more prior to the current date, and / or is on a special "Curios or Relics List" published by the BATF.

CURIOS OR RELICS FFL: Since 1968, in order to legally receive a firearm shipped across state lines, the recipient must possess a valid "Federal Firearms License" or FFL issued by the United States Department of the Treasury, Bureau of Alcohol, Tobacco, and Firearms (BATF).  There are many types of licenses; for dealers, for manufacturers, for importers and for firearms collectors.  The collector license (known as a Type 03 license) is unique in that it does not permit the licensee to engage in a business, but rather is specifically designed to enable the collector of old firearms.  Furthermore, the holder of a Type 03 license is restricted to receiving firearms that have been classified by the BATF as "Curios or Relics" as above. As a result of these specializations, the Type 03 Federal Firearms License is known as the Curios and Relics Federal Firearms License.  See also: CRUFFLE.

CURVED BARREL ADAPTOR:  A barrel attachment for the German MP44 Assault Rifle that allowed the gun to shoot around corners.  The MP44 or Machine Pistol Model 44 was a 7.92 x 33mm caliber rifle.  The curved barrel adaptor or attachment was effective for a few hundred rounds and included an optical periscope type mirror called a prismatic sight, that allowed the shooter to see around the corner or out of a room or trench.

Shoot Around Corners?

Periscope type "Prismatic Sighting System" on Curved Barrel Adaptor

The attachment was the fruit of experiments, carried out in Germany during the early1940s, with the object of providing a device which would enable troops to shoot from behind cover, without exposing themselves to enemy fire. Various deflecting troughs and curved barrels were tried with a number of infantry weapons, before the combination which is shown was developed.  The relatively short bullet fired by the MP44 made it particularly suitable for this role.  The attachment deflects the flight of the bullet through 30 degrees and, with the aid of the prismatic sight which is fitted, a reasonable degree of accuracy can be attained.  A further version of the device was developed which deflected the bullet through 90 degrees. This was intended for use as a close-defense weapon by armored vehicle crews; however it was found that bullets fired through it generally fragmented due to the stresses involved. 

German MP44 Assault Rifle with Curved Barrel Adaptor

The curved barrel device has proved something of a technological dead-end.  By contrast, the rifle itself was of fundamental importance in the development of modern military firearms, being the first "Assault Rifle" to see widespread use.  The assault rifle concept grew from a realization that the ammunition fired by conventional rifles was too powerful for normal combat use.  It could kill at over 2000 meters, but First World War experience showed that infantry firefights seldom occurred at ranges in excess of 400 meters.  Consequently it was perceived that smaller and less powerful cartridges could be used.  Although such thinking was current in several countries, Germany was the first to put it into practical effect. 

Using a shortened version of the standard rifle cartridge, an intermediate cartridge, the German assault rifle was able to deliver controllable fully-automatic fire against close-range targets, while still offering the possibility of accurate aimed fire out to all normal combat ranges.  This development revolutionized the infantryman's armament, rendering conventional rifles and submachine-guns obsolescent.  The concept was soon taken up by other nations, most notably by the Soviet Union with the famous Kalashnikov Avtomat (AK47).  Assault rifles are now standard equipment in armies throughout the world.  

For more information on Assault Rifles Click Here.

CUSTOM DEFENSIVE PISTOL:  An IDPA (International Defensive Pistol Association) division of competition for .45 ACP and 10mm shooters.  The division includes Colt & clone model 1911s, the Glock 20 and 21, the Para-Ordnance .45 ACP and STI / SVI type handguns in .45 ACP and 10mm chambering.  Abbreviated CDP.

CYLINDER: The rotating or revolving drum, found on revolvers, which contains multiple chambers.  Most commonly, a cylinder will contain six chambers, but some are made with as many as ten.  When a revolver is discharged, the cylinder is rotated by the action to bring the next chamber in line with the barrel.  2. The part of a revolver, immediately behind the barrel, that revolves and has a number of chambers into which cartridges are placed.  A cylinder can rotate left or right depending on the design of the revolver.

CYLINDER ARM:  In a modern solid-frame, swing out revolver, the U-shaped yoke on which the cylinder rotates, and which holds the cylinder in the frame.  Also called the crane.

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