.40 S&W

About .40 S&W

.40 S&W was designed to give .45-calibre effect in a 9mm-sized frame, and for two decades it was the American law enforcement standard. Its position has since eroded — most agencies that adopted it have moved back to 9mm as modern defensive bullets closed the performance gap that justified it.

That history is good news for buyers. Used .40 pistols are plentiful and cheap, magazines are widely available, and many .40 frames convert to 9mm with a barrel and magazine swap. The shooting characteristics are the trade-off: a sharper, snappier recoil impulse than either 9mm or .45, which some shooters dislike and which takes more work to shoot fast and accurately.