The original .357 SIG Federal 125 grain JHP with a nominal velocity of 1350 fps, was developed to reach a decent level of penetration, with ample expansion, and to work well after passing through initial barriers such as glass, metal, wood, etc. Since this cartridge is new, it does not have the great variety of ammunition for various purposes as the 40S&W enjoys. Obviously, if the cartridge continues to catch on, more variety in ammunition may be made available, to meet the various needs of rural, urban, and sports environments, including light lower pressure loads and higher maximum pressure loads, using a variety of light, medium, and heavy bullet designs. Also, from my own experience shooting the SIG P 229 in both 40S&W and .357 SIG, the perceived recoil appears to be somewhat similar between the two calibers, which I class as a bit more jolt than a 9mm, but very pleasant to shoot considering the high pressure magnum rounds. This article is based on the original SIG P 229 Federal bullet as described above. The author, Dr Topper, received assistance for the development of the article from the FBI Firearms Training Unit; But the opinions in the article belong solely to Dr Topper. Note: I have summarized many areas in the article for the sake of brevity.

The purpose of the FBI tests is to evaluate how ammunition will perform in all situations that agents may find themselves in. These tests were developed and formalized after the famous Miami incident.

The author said that out of the 8 testing categories of the 40 round evaluation, tests 6 and 8 are the acid tests. These two tests involve shooting at lightly clothed gelatin through automobile glass.

Besides the 40-round test, every load is checked for pressure, velocity, and accuracy.

Another important emphasis by the FBI besides penetration, is bullet placement.

The .357 SIG performance is equivalent to a 125 grain 357 Magnum with a 2 1/2" to 4" barrel length.

One complaint about the 357 and 9 ammo in similar grain loads as the 357SIG, is that they have limited penetration, especially after going through glass. The .357 SIG is designed to have controlled expansion and excellent penetration.

The .357 SIG held up as advertised. It exceeded 12 inches in all eight tests.

Dr Topper stated: "Average velocity from the SIG P 229 used in the gelatin tests was 1309 fps, and velocity from the test barrel was 1364 fps. Extreme velocity spread was only 55 fps from the SIG pistol and 47 fps from the test barrel, indicating excellent consistency in performance from both the ammo and the test gun. A 10-shot group from the test pistol averaged just 1.89 inches at 25 yards. The test barrel's group was only 1.14 inches, again indicating excellent performance from both the gun and the cartridge."

The pressure of the .357 SIG, 40,000 PSI, puts it into the magnum category, which means it can generate a lot of recoil. Since the SIG P 229 was designed as a magnum semiauto, recoil is very controllable and it kicks less than a medium weight 3" 357 revolver. It also holds 13 rounds compared to six rounds in a revolver.

The FBI tests showed that the .357 SIG round out-performed the 357 Magnum revolver and the very popular 9mm Luger semiautos.

Comparing the .357 SIG with the .40 S&W

The author compared the standard .357 SIG round, Federal 125 grain JHP, with a 40S&W round, Hornady 155 grain JHP. The SIG P 229 was used with the .357 SIG round, and a Glock 22 was used by the FBI to test the 40S&W round. Note: the Glock 22 has a barrel roughly 6/10" longer than the SIG P 229, so the test comparison is slightly flawed.

The results were very close. The Hornady .40 S&W bullet expanded more than the .357 SIG bullet did. The SIG pistol performed much more accurately than the Glock 22 at 25 yards, 1.89" as compared to 3.49" from the Glock. Dr Topper states:

"With respect to performance in gelatin, all rounds from both test loads shed their jackets after penetrating the glass in tests 6 and 8. However, the .357 SIG showed better penetration, going an average of 13 inches into the gelatin in test 6 as opposed to 10 inches for the .40. The Federal .357 SIG also out-penetrated the Hornady .40 by one to four inches in tests 2, 4, 5 and 7.

"The maximum pressure of the .40 load was 37,400 PSI, so one can expect that the .40 will be just about as hard on a gun of similar construction as the .357 SIG."

Both the .357 SIG and the .40 S&W beat the 9mm by a wide margin, as well as having very similar exterior ballistics out to 100 yards.

The author said the results show that the .357 SIG has about the same energy of a 155 grain 2nd generation .40 S&W round, along with the penetration capacity of a 180 again .40 S&W hydra-shok.

Dr Topper said, "However, for the shooter who wants it all (high energy, flat trajectory, high velocity, extreme accuracy, high firepower and deep penetration) in a single cartridge that fits in a cancelable, shootable handgun, the .357 SIG is just the ticket." The author then went on to say that the Federal 125 grain round might have a problem of over-penetration in certain urban environments. So the implication is to use the right kind of ammo for your intended application.

Dr Topper then said, "On the other hand, it would be an excellent caliber for a trail gun, and its effect on javelina and even small whitetails at ranges under 40 yards would be outstanding. If I were living back at my house in Northern Arizona, I imagine that a SIG P 229 in .357 SIG might soon replace both my .357 wheelgun and my .45 Gold Cup as the sidearm I'd carry when out in the backcountry."

Following is a chart taken from the above mentioned article in Handguns, April, 1996: