22 or 31? I'm trying to decide between the .40 and .357 sig. And should I get a new 4th gen or buy a used 3rd gen. Opinions? Thanks.
Is the 357 Sig bad? NO! It is a very reliably performing 9mm bullet, but it is does not offer significantly better terminal performance compared with the best current 9mm ammunition. When firing through heavy clothing, automotive steel panels, automobile windshield glass, interior wall segments, exterior wall segments, and plywood, both the 357 Sig Speer 125 gr JHP Gold Dot and 9mm Speer 124 gr +P JHP Gold Dot exhibited nearly identical penetration and expansion results THROUGH ALL THE DIFFERENT BARRIERS, as demonstrated by both our testing and that of the FBI. Most 357 Sig loadings, unless the fail to expand, do not offer excessive penetration; in fact, the exact opposite, under-penetration, can be a problem. Several .40 S&W and .45 ACP loads offered superior terminal performance through barriers compared to the 9mm and 357 Sig loads. In addition to having tested virtually all the handgun ammo available in lab settings, we have also had the opportunity to analyze numerous OIS incident forensic results and have not observed any greater incapacitation in actual shootings with users of 357 Sig loads compared to those users of 9 mm, .40 S&W, or .45 ACP who are using equivalent modern, well engineered ammunition.
The 357 Sig is not a bad cartridge, it just does not seem to offer anything that is not already available, at the price of less ammunition capacity than the similarly performing 9mm, as well as having greater recoil, muzzle flash, and wear on the weapon compared to other service pistol cartridges. On the other hand, since the 357 Sig is a modern cartridge benefiting from the latest engineering concepts, the bullets loaded with it have generally all been designed and tested using the latest FBI, IWBA, etc... testing protocols. This results in more robust terminal performance, less failures to expand, and thus greater tissue damage than will be found with older projectile designs. In addition, since according to data from Fackler and others, approximately 50% of shooting victims are incapacitated by psychological mechanisms, it is possible that the increased blast, flash, and noise of the 357 Sig enhances psychological perceptions of being shot.
In discussing this issue with an experienced ammunition engineer at one of the major ammo companies, he stated that he didn't particularly like the 357 Sig from an engineering perspective and described their difficulties in designing and producing 357 Sig ammunition which consistently performs as well as their ammunition in other service calibers. In particular, he felt his company's 357 Sig loads offered no better performance than their top 9 mm loads and stated their .40 S&W loads were superior in every respect to their 357 Sig ammunition. He firmly believes their .40 S&W offerings are the best performing duty ammunition his company produces.
We have found .40 S&W 180 gr to perform very well against barriers--better than the 9 mm and 357 Sig. The CHP used a variety of .357 Mag loads, depending upon what was available via the state contract. According to the published CHP test data, the .357 Magnum load used immediately prior to the CHP transition to .40 S&W was the Remington 125 gr JHP with an ave. MV of 1450 f/s from their duty revolvers--CHP has continued to report greater success with their .40 S&W 180 gr JHP than with the .357 Magnum 125 gr JHP they previously issued.