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Gun Glossary - Letter D
Index of Firearm & Gun Terminology

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DA:  Abbreviation for Double Action.

DAO:  Abbreviation for Double Action Only.

DAMASCENE:  The decorating of metal with another metal, either by inlaying or attaching in some fashion.   Damascene is often confused with Damascening or engine turning.

DAMASCUS BARREL:  A barrel made by twisting, forming and welding thin strips of steel around a mandrel.

DEBURRING TOOL: The deburring tool removes burrs from the inside and outside of newly-trimmed case mouths.

DECAP: To deprime a case by removing a spent primer from the primer pocket, most often accomplished by the decapping pin in a die during the resizing operation of reloading.

DECLARATION OF INDEPENDENCE:  Drafted by Thomas Jefferson between June 11 and June 28, 1776, the Declaration of Independence is at once the nation's (United States of America) most cherished symbol of liberty and Jefferson's most enduring monument. Here, in exalted and unforgettable phrases, Jefferson expressed the convictions in the minds and hearts of the American people. The political philosophy of the Declaration was not new; its ideals of individual liberty had already been expressed by John Locke and the Continental philosophers. What Jefferson did was to summarize this philosophy in "self-evident truths" and set forth a list of grievances against the King in order to justify before the world the breaking of ties between the colonies and the mother country. You are invited to read a transcription of the complete text of the Declaration of Independence below.

Note: This image of the Declaration is taken from the engraving made by printer William J. Stone in 1823 and is the most frequently reproduced version of the document. 
IN CONGRESS, July 4, 1776.

The original Declaration, now exhibited in the Rotunda of the National Archives Building in Washington, DC, is badly faded. Largely due to the  poor preservation techniques employed during the 19th century. 

Today, this priceless document is maintained under the most exacting archival conditions possible.

- High Resolution Images are available - 

These files are very large (8 to 10 megabytes) and will take approximately 1/2 hour or longer to download on a 56k modem connection. These images will print at approximately 24" wide by 29" high at 300 dpi (publication quality).

For graphic designers, each file also contains "clipping paths" for easy mask creation with most professional graphics software.

- For High Resolution Images - Click Here - 

The Declaration of Independence: A Transcription

IN CONGRESS, July 4, 1776.

The unanimous Declaration of the thirteen united States of America,

When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.--That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.--Such has been the patient sufferance of these Colonies; and such is now the necessity which constrains them to alter their former Systems of Government. The history of the present King of Great Britain is a history of repeated injuries and usurpations, all having in direct object the establishment of an absolute Tyranny over these States. To prove this, let Facts be submitted to a candid world.

He has refused his Assent to Laws, the most wholesome and necessary for the public good.

He has forbidden his Governors to pass Laws of immediate and pressing importance, unless suspended in their operation till his Assent should be obtained; and when so suspended, he has utterly neglected to attend to them.

He has refused to pass other Laws for the accommodation of large districts of people, unless those people would relinquish the right of Representation in the Legislature, a right inestimable to them and formidable to tyrants only.

He has called together legislative bodies at places unusual, uncomfortable, and distant from the depository of their public Records, for the sole purpose of fatiguing them into compliance with his measures.

He has dissolved Representative Houses repeatedly, for opposing with manly firmness his invasions on the rights of the people.

He has refused for a long time, after such dissolutions, to cause others to be elected; whereby the Legislative powers, incapable of Annihilation, have returned to the People at large for their exercise; the State remaining in the mean time exposed to all the dangers of invasion from without, and convulsions within.

He has endeavoured to prevent the population of these States; for that purpose obstructing the Laws for Naturalization of Foreigners; refusing to pass others to encourage their migrations hither, and raising the conditions of new Appropriations of Lands.

He has obstructed the Administration of Justice, by refusing his Assent to Laws for establishing Judiciary powers.

He has made Judges dependent on his Will alone, for the tenure of their offices, and the amount and payment of their salaries.

He has erected a multitude of New Offices, and sent hither swarms of Officers to harrass our people, and eat out their substance.

He has kept among us, in times of peace, Standing Armies without the Consent of our legislatures.

He has affected to render the Military independent of and superior to the Civil power.

He has combined with others to subject us to a jurisdiction foreign to our constitution, and unacknowledged by our laws; giving his Assent to their Acts of pretended Legislation:

For Quartering large bodies of armed troops among us:

For protecting them, by a mock Trial, from punishment for any Murders which they should commit on the Inhabitants of these States:

For cutting off our Trade with all parts of the world:

For imposing Taxes on us without our Consent:

For depriving us in many cases, of the benefits of Trial by Jury:

For transporting us beyond Seas to be tried for pretended offences

For abolishing the free System of English Laws in a neighbouring Province, establishing therein an Arbitrary government, and enlarging its Boundaries so as to render it at once an example and fit instrument for introducing the same absolute rule into these Colonies:

For taking away our Charters, abolishing our most valuable Laws, and altering fundamentally the Forms of our Governments:

For suspending our own Legislatures, and declaring themselves invested with power to legislate for us in all cases whatsoever.

He has abdicated Government here, by declaring us out of his Protection and waging War against us.

He has plundered our seas, ravaged our Coasts, burnt our towns, and destroyed the lives of our people.

He is at this time transporting large Armies of foreign Mercenaries to compleat the works of death, desolation and tyranny, already begun with circumstances of Cruelty & perfidy scarcely paralleled in the most barbarous ages, and totally unworthy the Head of a civilized nation.

He has constrained our fellow Citizens taken Captive on the high Seas to bear Arms against their Country, to become the executioners of their friends and Brethren, or to fall themselves by their Hands.

He has excited domestic insurrections amongst us, and has endeavoured to bring on the inhabitants of our frontiers, the merciless Indian Savages, whose known rule of warfare, is an undistinguished destruction of all ages, sexes and conditions.

In every stage of these Oppressions We have Petitioned for Redress in the most humble terms: Our repeated Petitions have been answered only by repeated injury. A Prince whose character is thus marked by every act which may define a Tyrant, is unfit to be the ruler of a free people.

Nor have We been wanting in attentions to our Brittish brethren. We have warned them from time to time of attempts by their legislature to extend an unwarrantable jurisdiction over us. We have reminded them of the circumstances of our emigration and settlement here. We have appealed to their native justice and magnanimity, and we have conjured them by the ties of our common kindred to disavow these usurpations, which, would inevitably interrupt our connections and correspondence. They too have been deaf to the voice of justice and of consanguinity. We must, therefore, acquiesce in the necessity, which denounces our Separation, and hold them, as we hold the rest of mankind, Enemies in War, in Peace Friends.

We, therefore, the Representatives of the united States of America, in General Congress, Assembled, appealing to the Supreme Judge of the world for the rectitude of our intentions, do, in the Name, and by Authority of the good People of these Colonies, solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States; that they are Absolved from all Allegiance to the British Crown, and that all political connection between them and the State of Great Britain, is and ought to be totally dissolved; and that as Free and Independent States, they have full Power to levy War, conclude Peace, contract Alliances, establish Commerce, and to do all other Acts and Things which Independent States may of right do. And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor.

The 56 signatures on the Declaration of Independence appear in the positions indicated:

Column 1

   Button Gwinnett
   Lyman Hall
   George Walton

Column 2

North Carolina:
   William Hooper
   Joseph Hewes
   John Penn

South Carolina:
   Edward Rutledge
   Thomas Heyward, Jr.
   Thomas Lynch, Jr.
   Arthur Middleton

Column 3

John Hancock

Samuel Chase
William Paca
Thomas Stone
Charles Carroll of Carrollton

George Wythe
Richard Henry Lee
Thomas Jefferson
Benjamin Harrison
Thomas Nelson, Jr.
Francis Lightfoot Lee
Carter Braxton

Column 4

   Robert Morris
   Benjamin Rush
   Benjamin Franklin
   John Morton
   George Clymer
   James Smith
   George Taylor
   James Wilson
   George Ross

   Caesar Rodney
   George Read
   Thomas McKean

Column 5

New York:
   William Floyd
   Philip Livingston
   Francis Lewis
   Lewis Morris

New Jersey:
   Richard Stockton
   John Witherspoon
   Francis Hopkinson
   John Hart
   Abraham Clark



Column 6

New Hampshire:
   Josiah Bartlett
   William Whipple

   Samuel Adams
   John Adams
   Robert Treat Paine
   Elbridge Gerry

Rhode Island:
   Stephen Hopkins
   William Ellery

   Roger Sherman
   Samuel Huntington
   William Williams
   Oliver Wolcott

New Hampshire:
   Matthew Thornton

External Resources on the Declaration of Independence 

The article "The Declaration of Independence: A History," which provides a detailed account of the Declaration, from its drafting through its preservation today at the National Archives.

"The Stylistic Artistry of the Declaration of Independence" by Stephen Lucas. By closely examining its language, this perceptive article sheds light on the Declaration as a work of literature and of persuasion. From Prologue, Spring 1990.

The Virginia Declaration of Rights strongly influenced Thomas Jefferson in writing the first part of the Declaration of Independence. It later provided the foundation for the Bill of Rights.

The Constitution

- Click Here - For High Resolution Images of Freedom's Documents -

DECLARING:  The process of notifying an airline that you are transporting a firearm.  See Traveling with a Firearm for further details.

DECOCK:  The process of un-cocking or returning the hammer or striker to the down or forward and unsprung position on a firearm.

DECOCK LEVER:  A lever which allows the gun to be decocked safely without pulling the trigger.  Also called a Decocking Lever or a Decocker.  Most commonly found on the SIG Sauer P series handguns and the new Heckler and Koch USP and Walther P99 models.

DEFENSE: A military combat mission exemplified by a coordinated effort by a force to defeat an attacker and prevent the enemy attacker from achieving there objectives.

Typical defensive missions are:

  • Defend in Sector:  A mission which requires a defending unit to prevent enemy forces from passing beyond the rear boundary of the sector, while retaining flank security, and ensuring integrity of effort within the scheme of maneuver.
  • Defend a Battle Position (BP):  A mission which places a unit in a BP to concentrate its fires, to limit its maneuver, or to place it in an advantageous position to counterattack.
  • Defend a Strong Point:  A mission which implies retention of the position at all costs.  Repeated assaults must be expected and repelled.

DIE: A tool, in hand loading, that reforms cartridge cases and seats bullets; or, in bullet manufacturing a tool that swages bullets or cores, extrudes lead wire or draws jackets.

DERRINGER:  A small single-shot or multi-barreled (rarely more than two) handgun or pocket pistol.  See below.

Derringer Pistol
The Derringer Pistol

To explode with great violence. It is generally associated with high explosives e.g. TNT, dynamite, etc., and not with the relatively slow-burning smokeless gun powders that are classed as propellants.

DNF:  Abbreviation for Did Not Finish as used in firearm competition to state the shooter did not complete the course of fire.

DOUBLE ACTION: A handgun mechanism where pulling the trigger does two actions; action one (1) retracts the hammer or striker and cocks the firearm, and the second (2) action releases the hammer or striker style firing pin to initiate discharge.  The opposite of Double Action is Single Action, where the trigger only performs one action, that is releasing the cocked  hammer.  All Single Action Firearms must be manually cocked.

Double Action Revolver: In reference to revolvers, "double action" means that it may be fired by just pulling the trigger to cock the hammer and fire the gun. 

Double Action Pistols (semi-automatics) can be cocked for the first shot by pulling the trigger to cock the firearm, then fire the gun.  The SIG P228 and Walther P38 are double action semi autos.

DOUBLE ACTION ONLY: Double Action Only or DAO guns are those which are fired by using the trigger to first cock the hammer and then fire the firearm for each shot.  Between shots, the hammer rests forward, uncocked.  Many Law Enforcement Agencies specify DAO side arms for safety and liability. 

DOUBLE BARREL: Two barrels on a firearm mounted to one frame.  The barrels can be vertically (over-under) or horizontally (side-by-side) aligned.

DOUBLE-BARRELED: A gun consisting of two barrels joined either side by side or one over the other.

DOUBLE BASE POWDER: Smokeless powder made with nitroglycerine and nitrocellulose base.

DOUBLE TAP: A quick succession to two-shots fired rapidly from a semiautomatic pistol, rifle or shotgun, or a revolver. Also, as a verb, to describe the act of firing a double-tap.   When doing a double tap the shooter does not line up (sight alignment or sight picture) the second shot.   They line up once, and then pull the trigger twice.  For most shooters (with some training) double taps can be practical and accurate at short distances.  In sport shooting competitions this can be a very valuable technique for saving time by clearing close targets very quickly.  NOTE:  Check with the staff at your local range before practicing double taps.  Some ranges do not allow shooters to fire more than one shot per second.

DOUBLE-SET TRIGGER: A device which consists of two triggers one to cock the mechanism that spring-assists the other trigger, substantially lightening trigger pull.

DOVETAIL: A flaring machined or hand cut slot that is also slightly tapered toward one end. Cut into the upper surface of barrels and sometimes actions, the dovetail accepts a corresponding part on which a sight is mounted. Dovetail slot blanks are used to cover the dovetail when the original sight has been removed or lost; this gives the barrel a more pleasing appearance and configuration.

DOWN RANGE:  The direction shots are normally fired on a range.  The area where the targets are set up.

DRAG: 1. Something that retards motion or action.  2. The retarding force acting on a body (as a bullet) moving through a fluid (as air) parallel and opposite to the direction of motion.  3. Friction between machined parts.  Also : retardation due to friction.  In Gunnery and External Ballistics the body or object effected by drag is the bullet or pellets fired from a gun.  The amount of drag varies depending on the density of the air, the square of the velocity, the air's viscosity and compressibility, the size and shape of the body [ projectile or bullet ], and the body's inclination to the flow.  In general, the dependence on body shape, inclination, air viscosity, and compressibility is very complex. One way to deal with complex dependencies is to characterize the dependence by a single variable. For drag, this variable is called the Drag Coefficient, expressed Cd.  - See below for more information on Drag and Coefficient of Drag.

What is Drag?
And How Does it Effect A Bullet In Flight?
By Matthew Mosdell of Lost River Ballistic Technologies, Inc.

     For a long time it was thought that the only force a bullet had to overcome was the force of gravity. Air was thought to have such a small influence on the path of a bullet that it was not even involved with determining early trajectories. Later, Benjamin Robins, using his ballistic pendulum, showed that the air had an influence 85 times greater than that of gravity on the flight of a bullet. Since that time great effort and energy have been involved in trying to minimize the effect air has on a bullets flight path. From the .75 caliber monster fired by Robins to the sleek .308 shot by many hunters today, drag has always posed a problem in accurately firing a rifle.

     There are many factors involved in understanding how air effects the trajectory of a bullet; some of these include air pressure (altitude), humidity, and temperature. All of these things effect the path of a bullet in flight, and must be considered to accurately fire a rifle. Other things that influence a bullets trajectory are the bullets shape, its spin ratio, and its velocity. This discussion will mainly focus on the laws of motion and how different forces (air pressure, humidity, temp.) influence the path of a bullet.

     Sir Isaac Newton (1642-1727) was perhaps the greatest scientist of all time. One of his greatest contributions to science, and the field of ballistics, was his formulation of the three laws of motion. The three laws of motion describe how things act with respect to gravity and forces which act upon them.

Newton’s First Law of Motion states:

A body remains at rest, or if in motion it remains in uniform motion with constant speed in a straight line, unless it is acted on by an unbalanced external force.

Newton’s Second Law of Motion states:

The acceleration produced by an unbalanced force acting on a body is proportional to the magnitude of the net force, in the same direction as the force, and inversely proportional to the mass of the body.

Newton’s Third Law of Motion states:

Whenever one body exerts a force upon a second body, the second body exerts a force upon the first body; these forces are equal in magnitude, and oppositely directed.

Each of these laws will help in understanding why a bullet behaves the way it does while in flight, and how external forces effect the ballistics of a projectile.


     First of all, the bullet in the chamber is “at rest” and must be acted upon to accelerate out of the barrel. This initial force is, of course, the burning of the gunpowder, which causes the subsequent expansion of gas forcing the bullet out of the cartridge, down the barrel, and toward the target. Interior ballistics is the study of this process; from primer ignition to the bullets exit from the barrel. The bullets flight path out of the rifle is influenced greatly by many variables inside the rifle, all of which play a part in the exterior and terminal ballistics of the bullet. 

     The expansion of the gas inside the cartridge is what drives the bullet to its maximum velocity; the gas taking the path of least resistance in the process of diffusion causes this velocity increase. With regards to Newton’s first law the process can be summarized as the bullet being the object at rest, and the expanding gas as the unbalanced external force. As the unbalanced external force acts on the bullet it pushes it out of the barrel. Another external force acts on the bullet as it is pushed down the barrel; this second force is the rifling, which produces the spin on the bullet and causes a gyroscopic stabilization of the projectile. Though there are other forces which act upon the bullet while in the rifle, consideration of these two very important variables will suffice, as they seem to be the most influential factors with regards to exterior ballistics.

     Now the bullet is in motion and, according to Newton’s first law, the bullet would stay in uniform motion unless acted upon by an external unbalanced force. So what are some of these external unbalanced forces? The most obvious is gravity; the other is air resistance, or drag. These two forces are what cause a bullet to deviate from its uniform path and they are the forces that constitute the study of exterior ballistics. Gravity and resistance to air are the forces that determine what requirements a ballistician must incorporate into a bullet to try to achieve the best flight possible. These two forces can be partially overcome by understanding Newton’s second and third laws of motion.

     Gravity is a constant; it is a force acting on a bullet pulling it towards the center of the earth at 32.0 feet per second squared. For example, after one second of flight a bullet has fallen 16 ft according to the constant force of gravity. It is an unbalanced force in that it only acts in one direction, down. The only partial solution to overcoming the effects of gravity is to increase velocity, because the faster the bullet goes toward a target the less time it has to be effected by gravity. Other than increased velocity there is very little that can be done to minimize the effects gravity has on a bullet.

     The bullets resistance to air is another force that acts to effect the flight of the projectile. Its influence is much greater than the influence of gravity, but the influence of air on a projectile can be reduced to a much greater extent than the effect of gravity. The general shape and design of our bullet are such as to optimally reduce the drag created from the bullet cutting through the air. Air can be considered an unbalanced force in that it acts on different parts of a bullet to differing degrees, which unless properly adjusted for can cause problems with stabilization. Most obviously the drag caused by air acts on the front of the bullet as the bullet pushes the air out its way. It also acts on the back of the bullet when a vacuum is created from the bullet flying through the air. We can apply Newton’s second law by saying a bullet is propelled toward a target by overcoming all the forces that are acting on it, and the more the effects of these forces can be minimized, the more optimal the flight of the bullet will be.

     Drag can be understood in very simple terms by applying Newton’s third law of motion. For every action there is an equal and opposite reaction, so for every particle of air the bullet has to move out of its way that particle of air exerts a force equal to its own mass and oppositely directed to the path of the bullet. This is the concept of drag. So it makes sense that at greater air pressure (more particle per space of air) there will be more drag on the bullet. This same concept applies to temperature (colder air is more dense), and to humidity (greater humidity equals lesser density). So if we can minimize the drag imparted by the bullet cutting through the air, the better it will fly. The problem with this is being able to minimize drag at high velocities, keeping the lethal potential of the bullet, and having the bullet hold together under the pressure of all the forces acting upon it.

     Additional problems with drag are introduced as a bullet approaches and surpasses the speed of sound. While at subsonic speeds a bullet has minimal amounts of drag acting on it and it is relatively easy to keep a stable accurate bullet at these low velocities. At transonic speeds, which begin at about 800 fps, a shock wave begins to form around the bullet as the air, which is being pushed aside, must move at about the speed of sound, (1120fps), to get out of the bullets way. The transonic speed that all bullets pass through when accelerating and decelerating is the most unstable speed. It is an inherently unstable speed because the bullet is beginning to form or lose a shockwave. What this means is that the air around the bullet cannot move out of the way fast enough, and so begins to pile up in front of the bullet. This is what makes aerodynamics very important in streamlining a bullet, and it is what makes it so difficult to stabilize a bullet. This transonic stage of a bullets flight is extremely turbulent and so it presents the largest problem for a ballistician to overcome in creating an accurate bullet at long distances. But, stabilizing a bullet with spin and increasing its aerodynamic properties can overcome these problems. 

     At transonic speeds a shockwave is beginning to form, as speed increases to supersonic this shock wave grows. This means increased drag from the shock wave requiring energy to be pushed along with the bullet. However, supersonic speeds are much more stable than transonic speeds, but the trick is getting a bullet through the transonic stage and retaining its stability. The bullet must provide the energy to push both itself and the shock waves produced in the transonic and supersonic speeds through the air. This increased energy required to propel both the bullet and the shock wave through the air is another force which must be considered when understanding the effects of drag on a bullet.

     At high velocities, under all these forces, many bullets will simply fall apart, or vaporize. So in order to allow a bullet to hold together there were limitations placed on what a bullet could do, and more than anything else velocity was sacrificed. At Lost River Ballistic Technologies we don’t believe in sacrificing velocity, because more velocity means more energy transferred to the target, which means more lethality. So we decided to make bullet’s that can hold up to the intense forces put on them at high velocities. We have also maximized our bullets resistance to the effects of drag by giving the best shape and balance so as to streamline the bullet in flight. With this new design we have decreased the effects of drag and increased velocity. By increasing velocity we decrease the effects of gravity with respect to distance traveled by the bullet and increase lethality. By finding a way to reduce the effects of gravity and air drag while increasing lethality we have come to offer the best hunting bullet ever.

Information Courtesy of:
Matthew Mosdell

Lost River Ballistic Technologies, Inc.
Post Office Box 801
Arco, Idaho 83213

Telephone: 1-888-807-8611
Local: 1-208-527-8611 
Fax: 1-208-527-8613

Web URL: www.LostRiverBallistic.com

A single variable used to characterize the very complex dependence of the variables that characterize drag.  These dependant variables include the shape, inclination, velocity squared, compressibility and air viscosity. In Gunnery and as Drag Coefficient [ Cd ] relates to external ballistics, a higher Cd is preferred for accuracy and bullet performance in flight.  

Algebra Update:  For those of us who have fired a few boxes of ammo since our last algebra class, here is the definition of COEFFICIENT.


  1. A number or symbol multiplied with a variable or an unknown quantity in an algebraic term, as 4 in the term 4x, or x in the term x(a + b).
  2. A numerical measure of a physical or chemical property that is constant for a system under specified conditions such as the coefficient of friction.

Drag coefficient is proportional to { (gravitational force) / (inertial force) } and is used in momentum transfer in general and free settling velocities and resistance to flow calculations in particular. 

It is normally defined in the following form:

C_d=(g.{rho-rho_f}.L) / (rho.V2)





= Gravitational acceleration


= Characteristic dimension of object


= Density of object


= Density of surrounding fluid


= Velocity

DRAM: Measure of weight equal to 27.34 grains. There are 16 drams per ounce; 256 drams per pound.

DRAM EQUIVALENT:  Term used to indicate the approximate velocity of a shot charge by a comparison.  When shotgun shells were loaded with black powder, the powder charge was measured in drams.  Dram equivalents were originally developed in the early 20th century to allow sportsmen an easy method of comparing the ‘new’ smokeless powder loads to the then more familiar black powder loads.  Used in connection with shotgun shells to describe how powerful they are, by equating their power with an equivalently powerful black powder load. The higher the number, the more powerful the shell is.  Overall, the most important thing to remember is that the higher the dram equivalent, the higher the velocity for a given shot weight and, as a result, the more powerful the charge. There are no real dram equivalents for loads that didn't or couldn't exist in the black powder era.  Key examples of these are steel loads and some of the heavy magnum turkey loads.  

WARNING: Dram equivalents values have no relationship to the actual powder charge in a shell.  These values should never be used in determining smokeless powder charge weights.  There are no real dram equivalents for loads that didn't exist in the black powder era.

DRIFT: Deviation of a projectile from the line of departure due to its' rotational spin or the force of wind.  2. The sideways movement of the bullet in flight, caused by the rifling.  Note: The sight is usually designed to provide an average compensation for drift at the usual range over the firearms employment, but additional adjustment may be required for longer ranges.

DRILL: The training of soldiers in marching and the manual of arms. (as in Drill & Ceremonies) 2. An implement with cutting edges or a pointed end for boring holes in hard materials, usually by a rotating abrasion or repeated blows; a bit.

DRILL SIZE:  Measurement of the bit or cutting implement used to bore holes.

Drill Size to Decimal Fraction Table

80 .0135   1/8 .1250   O .3160
79 .0145   30 .1285   P .3230
1/64 .0156   29 .1360   21/64 .3281
78 .0160   28 .1405   Q .3320
77 .0180   9/64 .1406   R .3390
76 .0200   27 .1440   11/32 .3438
75 .0210   26 .1470   S .3480
74 .0225   25 .1495   T .3580
73 .0240   24 .1520   23/64 .3594
72 .0250   23 .1540   U .3680
71 .0260   5/32 .1562   3/8 .3750
70 .0280   22 .1570   V .3770
69 .0292   21 .1590   W .3860
68 .0310   20 .1610   25/64 .3906
1/32 .0312   19 .1660   X .3970
67 .0320   18 .1695   Y .4040
66 .0330   11/64 .1719   13/32 .4062
65 .0350   17 .1730   Z .4130
64 .0360   16 .1770   27/64 .4219
63 .0370   15 .1800   7/16 .4375
62 .0380   14 .1820   29/64 .4531
61 .0390   13 .1850   15/32 .4688
60 .0400   3/16 .1875   31/64 .4844
59 .0410   12 .1890   1/2 .5000
58 .0420   11 .1910   33/64 .5156
57 .0430   10 .1935   17/32 .5312
56 .0465   9 .1960   35/64 .5469
3/64 .0469   8 .1990   9/16 .5625
55 .0520   7 .2010   37/64 .5781
54 .0550   13/64 .2031   19/32 .5938
53 .0595   6 .2040   39/64 .6094
1/16 .0625   5 .2055   5/8 .6250
52 .0635   4 .2090   41/64 .6406
51 .0670   3 .2130   21/32 .6562
50 .0700   7/32 .2188   43/64 .6719
49 .0730   2 .2210   11/16 .6875
48 .0760   1 .2280   45/64 .7031
5/64 .0781   A .2340   23/32 .7188
47 .0785   15/64 .2344   47/64 .7344
46 .0810   B .2380   3/4 .7500
45 .0820   C .2420   49/64 .7656
44 .0860   D .2460   25/32 .7812
43 .0890   1/4 .2500   51/64 .7969
42 .0935   E .2500   13/16 .8125
3/32 .0938   F .2570   53/64 .8281
41 .0960   G .2610   27/32 .8438
40 .0980   17/64 .2656   55/64 .8594
39 .0995   H .2660   7/8 .8750
38 .1015   I .2720   57/64 .8906
37 .1040   J .2770   29/32 .9062
36 .1065   K .2810   59/64 .9219
7/64 .1094   9/32 .2812   15/16 .9375
35 .1100   L .2900   61/64 .9531
34 .1110   M .2950   31/32 .9688
33 .1130   19/64 .2669   63/64 .9844
32 .1160   N .3020   1 1.000
31 .1200   5/16 .3125      


DRILLING:  German for "triple", which is the designation for a three-barrel gun.  Drilling configurations typically consist of 2 shotgun or smooth bore barrels and one rifle barrel.

DROP:  The distance a bullet or projectile falls, calculated from the line of departure.

DROP FREE:  As in Drop Fee Magazine.  A drop free magazine is one that falls (assisted only by gravity) when the magazine release is pressed.   Drop free magazines are generally considered desirable for speed reloads since the shooter does not have to handle the empty magazine. They simply allow the empty magazine to fall to the ground while reaching for the fresh magazine.

DRY FIRE:  Simulated firing of an unloaded firearm for practice or function check.  Done by first ensuring the firearm is unloaded by opening the action and visually inspecting the chamber, then pulling the trigger, bringing down the hammer and advancing the firing pin. 

Instructors often encourage dry firing as a training technique.  By firing the gun unloaded a shooter becomes accustomed to pulling the trigger without flinching or jerking in an attempt to control recoil.  This is also a method used to develop hand eye coordination and sight alignment techniques.

Before you attempt such exercises, be very sure that the gun is unloaded.  Then check again. Don’t just check the magazine but make sure that there is no round in the chamber by visually inspecting it and inserting you finger into the empty chamber.   If you plan to practice dry firing with your firearm it is advisable to remove all ammunition and magazines from the room and only point the unloaded firearm in a safe direction as you practice trigger control and point of aim techniques.  You can’t be too careful about this!

DRY FIRING: Technique used in a training exercise wherein the shooter employs all the factors of controlling the firing of an accurate shot without using live ammunition.  Great practice for sight alignment and trigger control.  Dry Firing normally does not hurt or damage most modern handguns.  If unsure, check with the specific manufacturer or a certified armor or gunsmith for your handgun.

DSHK: also written DShK: Degtyarov-Shpagin Krupnokaliberny - Russian / Soviet 12.7 mm Heavy Machine Gun (HMG).  The DShK is a Russian 12.7 mm heavy machine gun developed during the 1930s, and produced from 1938 to 1980. The DShK takes a 50 round belt and fires at a rate of 550 to 650 rounds per minute with a muzzle velocity of 860 meters per second (m/s).  The DShK was the standard multi-role Heavy Machine Gun (HMG) of the Soviet Military. The DShK was fielded in 1938 and subsequently used during "The Great Patriotic War" (a.k.a. WW II) and with modifications and updated configurations, is still is service with the Russian military and several other countries to the present day.  The DShK is widely used around the world from Afghanistan to Vietnam to Africa to Central and South America.  Like the famous AK-47 Assault Rifle, this well made Heavy Machine Gun was widely exported, sold and given to East Block and Warsaw Pact allies by the Soviet Union for use by it allies all over the world.  See details, graphics and technical specifications for the DShK below.

Great Guns of the World
Degtyarov-Shpagin Krupnokaliberny
Soviet DShK 12.7mm HMG

DShK 12.7mm Heavy Machine Gun from Kubinka Muzeum 
( photo by Evgeniy Boldyrev )

DShK Technical Specifications:

The DShK (Degtyarov-Shpagin Krupnokaliberny) 12.7-mm Heavy Machine Gun is a gas operated, belt fed, air cooled weapon which fires from the open bolt position.  The DShK has a rate of fire of approximately 650 rounds per minute.  In Anti-Aircraft (AA) mode, the rounds are effective out to 3,000 meters with a maximum range of 5,000 meters.  The model 38/46 has a shuttle feed housed in a flat, rectangular cover.  It has reversible feed; that is, with a minor adjustment the ammunition belt can feed from either the left or the right side. It also has a quick change barrel. The FSU use the DShK extensively as an antipersonnel and antiaircraft armament on medium tanks and armored personnel carriers.  It is capable of full automatic fire only.  The Soviets adopted the original DShK (model 38 or M1938) in 1938 as a ground-mounted, dual-purpose antiaircraft and antitank gun.  

Largely superseded by the 14.5 mm ZPU-series weapons in the antiaircraft role, the ground mounted version has become obsolete.  In 1946, the Soviets adopted the improved version (model 38/46 or M1938/46, also known as DShKM) with a modified feed mechanism and a quick-change barrel.  It is still in use as a vehicle mounted armament.  When used as a tank or Armored Fighting Vehicle (AFV) mounted machine gun, it is known as the DShKT.  See below for more technical and historical information.

Historical Perspective:

It should be stated here for the neophytes to World War II history or for the young folks of the "Cold War" generation, that the Russians known then as the Soviet Union were allied with the United States, Great Britain, Canada, Australia and the so called "Allies" during World War II.  The Russians refer to World War II as the "Great Patriotic War" and they suffered more casualties than all of the other countries involved in the war combined.  The Russians and the Soviet peoples also killed more NAZI Germans than all of the allied countries combined and the fighting on the "Eastern Front" was with out a doubt the most deadly and brutal fighting of the war.

DShK Russian / Soviet
12.7mm Heavy Machine Gun
Steve Hill fireing his Russian DShK HMG
Steve Hill of Spotted Dog Firearms firing his Russian DShK 12.7mm HMG

Model: DSHK Model 1938
Caliber: 12.7mm *
Operation: Gas. ( Adjustable )
Weight: 75 pounds
Length : 64 inches
Barrel: 39 3/8 inches
Belt Capacity: 50 round linked sections
Cyclic Rate: 550-650 rounds per minute
Sights: 200-3500 meters
Ground Mount: Model 1938**
Weight: 234 pounds
Armor Shield: 60 pounds

*12.7mm Ammunition case length is slightly longer than U.S. 50 Cal. BMG

**With the mount adjusted for Anti Aircraft (AA) use, there is a 360 degree traverse and a maximum elevation setting of approximately 85 degrees.

The DSHK 38 is a "Heavy Degtyarev" design. The gun was adopted and the first units placed into service with Soviet ground forces in 1938.  The model 38 had a rotating circular type of feed block similar to a cylinder of a revolver. The cylinder carries the cartridges in its recesses as they are removed from the belt. The cylinder rotates from left to right stripping the cartridges from their belt. This rotation brings the rounds into alignment with the chamber where they are forced into battery by the bolt.

The DSHK38 was a considerable success. The DSHK with its adjustable gas system , the extreme reliability of the Degtyarev system, and the "punch" of a powerful 12.7 mm round made the gun an extremely desirable piece of combat weaponry for Soviet forces. As a general rule the DSHK 38 was effective on medium tracked or wheeled armor at a range of approximately 300-400 meters.  

Afghan Rebel with DShK 12.7 mm HMG

Some DShK model 1938's and their later modification (model 38/46) can still be seen in service today on Russian and CIS AFV's and in Anti-Aircraft, Ground Defense and Vehicular Mounted configurations in many parts of the world.  

The DSHK 38 was not strictly an Infantry weapon. The model 1938 was mounted pretty much on anything that was big enough to carry it.  

The DSHK 38 was also used on shipboard as well as other locations in an Anti-Aircraft role. The DSHK was also mounted on armored transport vehicles, armored trains and track driven armor.

In the Infantry application the DSHK 38 was issued with a wheeled ground mount. This ground mount was equipped with an Armored shield designed to protect the machine gun team by deflecting rounds and explosive debris of up to .30 caliber. The Mount could be easily converted to an Anti-Aircraft or elevated position by the machine gun team. The wheels and shield are easily removed and the mount can be converted in a matter of seconds by a well trained crew.

The DSHK 38 was never replaced by the Soviet Union during World War II. The minor wartime modifications can be can be attributed to manufacturing problems rather than to defects in design.  The DSHK 38 was modified in 1946. This model was identified as the 38/46.  The difference between the 38 and the 38/46 was the simplification of the feed mechanism. The feed mechanism of the DSHK38/46 is an enlarged version of the feed mechanism on the Soviet RP46 7.62mm Light Machine Gun (LMG).

12.7 mm Ammunition

There was a variety of 12.7mm ammunition available for the DSHK Mod. 38.  The tips of the projectiles were color coded for rapid recognition.  Some examples available to Soviet Machine Gun Crews were: 

12.7 mm AP Armor Piercing
Color Code: Black Tip
Projectile Weight: 801 grains
Muzzle Velocity:  2820 fps
12.7 mm AP-I Armor Piercing Incendiary
Color Code: Black & Red Tip
Projectile Weight: 721 grains
Muzzle Velocity: 2880 fps
12.7 mm AP-I-T Armor Piercing Incendiary Tracer
Color Code: Violet & Red Tip
Projectile Weight:  674 grains
Muzzle Velocity: 2930 fps

DShK Heavy Russian Machine Gun information courtesy of Steve Hill and Spotted Dog Firearms at Telephone 1-602-538-2769.

E-mail Steve Hill at [email protected]

DUD: Slang for a cartridge that fails to fire after its primer is struck by the firearm's firing pin. See also Charles "Boomer" Schumer, Sister Sarah Brady, Algore, "Barb Wire" Barbara Boxer, Bill "Bubba Dick" Klinton and "Dooms Day" Dianne Feinstein.  For an unbiased look at the Anti Duds see - The "Anti" Defined - on the Gunnery Network RKBA Web.

I really have no clue....
Typical Political Dud.
"Hey Bill... is this thing loaded?"

A British military bullet developed in India's Dum-Dum Arsenal [No not kidding] and used on India's North West Frontier and in the Sudan in 1897 and 1898.  It was a jacketed .303 cal. British bullet with the jacket nose left open to expose the lead core in the hope of increasing effectiveness. Improvement was not pursued, for the Hague Convention of 1899 outlawed such bullets for warfare. Often "dum-dum" is used as a term for any soft-nosed or hollow-pointed hunting bullet, though technically incorrect.

DUPLEX LOAD: The use of two different powders in loading the same cartridge.

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12924 Highway A-12
Montague, CA 96064
Tel: (916) 459-5445
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To reach Dynamit Nobel - RWS 

Dynamit Nobel - RWS
81 Ruckman Road
Closter, New Jersey 07624
PHONE: 201-767-1995
FAX: 201-767-1589


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