[Tijeras_Slim]

We're all students until the day we die.

I hope somebody comes up with a historical explanation why the .38-40 (.38 WCF) is actually a 40 cal before I shuffle off this mortal coil.

[yarddog]

The 38-40 is an oddball and I am not sure how it got it’s name but I bet it has something to do with the fact that 41 Long Colt and 38-40 both share the same diameter barrels which is around .401-403.

The 41 Colt has been loaded with actual .385 hollow base bullets which expanded when fired to fill the bore. This is similar to how the .22 rimfires work. Interestingly the case on a .41 Colt is .41 Caliber.

Of course the 40 in 38-40 comes from the charge of 40 grains of black powder which it was originally loaded with. I guess whoever designs a cartridge gets to name it.

[Disambiguator]

I hope somebody comes up with a historical explanation why the .38-40 (.38 WCF) is actually a 40 cal before I shuffle off this mortal coil.

I want to know why the .44 Magnum is actually a .43.