In the dim and distant past.......before there was an Internet.......perhaps before there was air--there was the 38/40 WCF.
Circa 1975 a lot of development was being done on cartridges and platforms to bridge the "gap" perceived between the 9mm and 45 ACP in the semi-auto pistol universe. The 10mm came first (commercially), and was little more at first than cut-off 30 Remington brass and 38/40 bullets blended into a very capable cartridge. Among those first bullets were both jacketed and cast 38/40 projectiles, which worked very well since the JSP designs were built to expand in the same 1200 FPS envelope that a Winchester '73 was meant to run in. Norma Projektilfabrik got into the act, and produced 200 grain bullets for the caliber and loaded them to run 1200 FPS in the Bren Ten--which absorbed these beast-loads with aplomb. Colt and clones of the 1911 persuasion......not so much. The 175 grain W-W Silvertips @ 1250 FPS are about as hot as a Colt should be run with, and I use that as my stop point with my Glocks too.
The 40 S&W was designed to fit the frame geometries of 9mm platforms. FBI found out early-on that a lot of their personnel had trouble managing the 10mm recoil and bark, and 10mm Lite (still loaded by Federal) resulted. The 40 S&W's ballistics and performance envelope is a close imitation of 10mm Lite, 180 grain JHPs in the 950-1000 FPS ZIP Code. The 40 S&W case is just a 30 Remington (again) punched with a small pistol primer pocket.
I like the 40 S&W. My subjective opinion is that the 40 is a mite harder to handle that the 45 ACP in terms of recoil and bark, but among the troops at my old shop it is the consensus favorite caliber. I like all four calibers, and load all four calibers. I don't carry the 9mm due to our ^&%$-poor authorized ammo that can't make decisive stops on JACKRABBITS in that caliber, but with better ammo I would move the 9mm into my carry rotation. My usual in-town armament is OC gel canister and Glock 23. Thankfully, no usage of either so far--but a close call a year ago and a few others from time to time. I like the 40 S&W as felon repellent, but the 45 ACP is no slouch. 10mm is my longtime favorite, though. Basically, the 40 S&W duplicates 38/40 performance from a revolver; 10mm duplicates 38/40 performance from a '73 Winchester. There truly is nothing new under the sun.
