It's a Remington No. 4 revolver. No caliber is marked, but it's a centerfire. I read that this gun was made in both .38 and .41. But what ammo will fit it? In .38, there is: .38 S&W .38 Long Colt .38 Short Colt .38-40 .38 Colt Navy .38 Special In .41, there is: .41 Short Colt .41 Mag (probably not) Any help?