Sig Sauer P239 SAS .357sig Conversion

If you read the forums, you won’t find too many .357 sig fan boys.  You may even be lead to believe that the .357 sig is a passing fad.  H&K quit making a .357 sig model.  I believe the primary reason the .357 sig is the least popular self defense round is the cost of the ammo.  Its the most expensive, hardest to find and most difficult to hand load of the most common handgun rounds (.380 through .45).

Many gun owners don’t realize what a great defensive round the 357 sig is. The ammo is expensive, which is why I think the larger agencies have stayed with .40 caliber. Federal Air Marshals, the Secret Service and Texas DPS carry this round in their standard issue pistols because it spreads out considerably more than the 40 S&W when penetrating a target.

We purchased the P239 before I retired from DHS HSI. It was not approved for carry back then but last year DHS, decided to purchase Sig P229 DAK pistols as their standard service weapon.

We purchased a .357 sig barrel from Sig Sauer and dropped it in our P239SAS.  I’ve shot the SIG SAUER P239 in .357 sig with only 200 rounds so far. The SIG SAUER P239 (henceforth called the P239) is a single-stack, semi-auto pistol with classic SIG SAUER features, including a hard coated anodized aluminum frame and a stainless steel slide. It comes in the DAK, SRT, or DA/SA trigger. My model is a DAK trigger version, originally sold as a .40 S&W model.

This gun has performed without a hitch having fired over 1,000 rounds of .40 S&W before converting to .357 sig.  The P239 is a smaller and slimmer version of the P229 and the SAS model comes out of the Sig Custom Shop.  SIG SAUER uses quality components like hardened roll pins and full-length slide rails. The barrel and chamber of the P239 (and the P229) are markedly reinforced compared to most compact handguns.  This suits the .357 sig round, which is loaded considerably hotter than the .40 caliber round.

The DAK trigger is a smooth double action trigger that gives the user the same pull all the time if the shooter allows the full reset.  There is no decocking lever on DAK models. After the pistol fires and the trigger is released forward, the trigger has an intermediate reset point that is approximately halfway to the trigger at rest position. The trigger pull from this intermediate reset point is 38 N (8.5 lb). If the trigger is released all the way forward, this will engage the primary trigger reset and have a trigger pull of 29 N (6.5 lb). To engage the intermediate reset, the trigger must be held to the rear while the slide is cycled, either manually or by the recoil of a round being fired.

The .357 SIG cartridge was designed to mimic the .357 magnum in an auto pistol. It is a bottleneck cartridge, which means the bullet has a narrower diameter than the base of the cartridge. In this case, the bullet diameter approximates a 9 mm bullet and the base of the cartridge approximates a 40 caliber cartridge.

The .357 magnum had a reputation of excellent performance in ballistic gelatin tests, especially after barrier. That is, one fires through tempered glass into ballistic gelatin to test one aspect of bullet performance. There are several factors including the weight retention of the recovered bullet, the amount of expansion and what it actually does inside the gelatin.

FBI tests resulted in the .357 SIG cartridges generally duplicating or exceeding the 357 magnum performance, except in heavier bullet weights. It appears that the nominal bullet weight for the 357 SIG was about 124 grains, simply because the 124 grain combinations were more accurate and tore up the gelatin.  The 357 SIG gave after-barrier performance, which could only be described as remarkable.

SIG SAUER has a reputation for design ergonomics in their handguns, which are more expensive than most of the other major manufacturers.  The P239 should fit a variety of shooters comfortably, especially the grip angle, which tends to absorb the recoil of this cartridge. The inherent design advantages of the 357 sig cartridge are perfect for this handgun. I am able to shoot a superior cartridge that feels like a +P 9mm in a handgun package small enough for comfortable concealed carry.  The carry weight (7+1) of my P239SAS is just over 2 lbs.

Another reason to carry this gun in .357 sig caliber is its accuracy.  Using duty rounds, I consistently hitting 4’ steel plates at 50 yards during my first test.  The only handgun that I consistently shoot more accurately than my P239 is my single action S&W 1911SC series E .45 ACP pistol. 

Here’s a good video on the Sig P239 SAS from my YouTube buddy Tom at Weapons Education

“The great object is that every man be armed.” and “Everyone who is able may have a gun.”
Patrick Henry

Update on Tuesday, October 2, 2012 at 2:35PM by Bonzer Wolf

By the way my carry ammo is .357 SIG Winchester PDX1 Defender Bonded JHP. Here’s an Ammo Test video from  TNoutdoors9 on YouTube.  TNoutdoors9 regularly posts very informative ammo tests on many differnet brands and calibers of ammo. I find them very useful in helping me decide what ammo to carry.