.40 S&W Concealables: M&P40 Edges Out Sigarms’ P229 SAS

The ammo development program at Winchester had been a closely guarded secret. The goal: to make a suped-down version of the 10mm Auto.

When the FBI began testing the 10mm, the agency found that a 180-grain bullet with velocities between 950 to 1,000 fps had great defensive potential. But the 10mm Auto, introduced in 1983, was too hot and dealt the shooter too much recoil for practical law enforcement use. What was needed, essentially, was a shortened 10mm cartridge that would fit in a smaller pistol platform—that is, S&W’s 9mm frames. Also, the cartridge needed to deliver a 180-grain payload at 950 to 1,000 fps with chamber pressures under

Top left, the P229 SAS (Sig AntiSnag) is a SigArms Custom Shop limited-production gun that has been dehorned. The $995 SigArms P229 SAS comes with the new Sig Sauer pistol Custom Shop Grips, which we show in detail elsewhere. Top right, the FN Herstal FNP-40, $695, was a DA/SA gun similar to one we tested in December 2006, which came with 10-round magazines. This gun included 14-round magazines and Trijicon night sights, which upped its price. Bottom left, we tested a Smith & Wesson M&P40 in the August 2006 issue, putting it head to head with a Springfield XD 45. Pitted against other .40s in a slightly different configuration here, this $495 test gun came with two 15-round magazines and a standard Novak Lo-Mount rear sight, and we graded it an A- autoloader.