The .41 Magnum revolver cartridge and the 10mm Auto round are often compared as equals. They aren’t, but when you start looking at them, it’s downright eerie how much they have in common.

Each was originally intended for combat work, and each — the .41 in 1964, the 10mm in the late ’80s — was ballyhooed as the next ideal police handgun cartridge. Each had some spectacular early adoptions (San Francisco, Amarillo, and San Antonio for the .41, FBI and the state troopers of Virginia and Kentucky for the 10mm), but neither caught fire in popularity and neither is much seen anymore in law enforcement. In both cases, an arguably exaggerated perception of excessive recoil had a lot to do with that.

Each is a flat-shooting cartridge and both retain energy well at longer distances. Each benefits from a broad power range in available loadings, but neither was introduced in an optimum cartridge format, hurting their popularity. The .41’s police load was a non-expanding 210-grain lead semiwadcutter at 950 to 1,000 feet per second. It delivered reasonably good stopping power but generally shot through and through the felon, creating unacceptable danger to bystanders behind him.

The first 10mm Auto ammo was by Norma, in tandem with the Bren Ten project. The Norma hollowpoint was too toughly jacketed to open reliably, and the 200-grain, 1,200 fps jacketed truncated cone configuration was powerful enough to crack the steel of the early Dornaus & Dixon Bren Tens, and was horrendously over-penetrative. Larry Kelly Magna-Ported the extended inch of a 6" Bar-Sto barrel on my Colt Delta Elite 10mm, and shot a big wild hog with one of those Norma 200-grain JTCs. The bullet entered the front of the chest and exited the rear ham. It was a one-shot kill, but that bullet could have killed three or four men standing in line facing the shooter. By the time good hollowpoint loads had been developed for both .41 Magnum and 10mm, each caliber had lost its momentum in the race for popularity.

Both cartridges lent themselves well to carbines. The FBI still has some HK carbines in 10mm, only now being traded out for .223s, with their S&W 10mm pistols already consigned to the FBI Museum. Marlin briefly produced its excellent 1894 lever action in .41 Magnum. Similarly, each has been chambered in the type of handgun opposite what it was designed for. The .41 Mag revolver cartridge has been offered in the Desert Eagle auto, and the 10mm Auto proved deliciously accurate in the S&W Model 610 revolver.