:)In the old days the Army used two .45s for a while. a Shoenfield (spelling??)(double action top break revolver) and a Colt single action. The Shoenfield used a 45 caliber "russian" I think it was called, used a shorter cartridge, the single action Colts used the .45. When the guys at the forts ordered ammo they often wrote ",45 caliber ammo short" and ".45 caliber ammo 'Long" ( as both guns were issue)and many folks started calling the .45 Colt the "Long Colt" or .45LC. Of course the .45 ACP has nothing to do with this!! The proper name is .45 Colt.
Bullet diameter and the name of the cartridge are not always the same.
Carl