I had read about firing pin issues with these and with that in mind checked it before I bought it. This one has an inertial firing pin. I'm not sure if that means it was replaced at some time or not as I've read early ones do not have inertial pins but later ones do. At 1948 and second year of production, this would be a very early one considering they made them into the 1980's. But then again, they may be referring to the entire line which began in 1921. They became "Super" in 1946 with the addition of the quick disassembly leaver and a few other changes. I thought it strange at the time because I never really investigated firing pins much and assumed it would protrude when the hammer was against it. It does not. But it looked like a normal pin and we figured it must be inertial to drive into the firing pin. Checked my 1911 when I came home and it is the same way. As for other ammo, I've read that while it can be done, it's not recommended. With inexpensive brass, I"m not going to worry about it. I don't shoot a lot and if I load 200 rounds, it's going to last me a while.