Versatility Of The .40 S&W Cartridge
The .40 is essentially the auto version of the .38-40 revolver cartridge of 19th century frontier days and may only be exceeded by the .357 Magnum revolver round in availability of different commercial ammunition for different needs. The original (and still most popular) .40 loading is a 180-gr .400″ diameter bullet at around 1,000 feet per second, generating some 420 foot-pounds of energy (fpe); the .38-40 bullet was 0.401″ in diameter at 975 fps and 380 fpe. The .40, of course, comes with better designed, more effective projectiles.
The .45 Auto? The same 185-gr. .40 load at 1,000 fps and 420 fpe compares quite favorably to the yesteryear-favorite .45 ACP load of 185-gr. at 1,000 fps and 411 fpe. It comes close to the .357 Magnum, whose contemporary ammo sends a 158-gr. bullet at 1,235 fps and 535 fpe, where the .40 launches a 155-gr. slug at 1,200 fps and roughly 500 fpe, or a 165-gr. projectile at 1,150 fps and 485 fpe. In lighter bullet loads, the .357 Mag 125-gr. hollow point at 1,450 fps and 583 fpe isn’t far off from a 135-gr. .40 loaded to 1,325 fps and generating 526 fpe. And let’s not disregard the boutique ammo makers who offer heavy, hard-cast .40 bullets at speeds which can ruin a bruin for those who just gotta hike where there are big bears but don’t want to spring for a 10mm or a .44 Magnum.
Need something milder? During the early days of the FBI issuing the .40, they had a light 165-gr. load, colloquially called the “minus-P,” running at 980 fps with 350 fpe. This is a bit hotter than the .38 Special “FBI Load,” a 158-gr. all-lead semi-wadcutter hollow point at 890 fps 270 fpe — I found it fit to kick in a GLOCK 22 about the same as the hottest police load for the 9mm in the same-size GLOCK 17 with the Winchester 127-grain +P+. Handloaders found it could be made even softer for competition: I’ve seen Scott Warren and Steve Koski use .40s to win overall in major Stock Service Pistol matches against 9mm shooters in IDPA competition, Scott with the S&W M&P and Steve with the GLOCK 35.