[deafsmithco]

I had the same thing happen back in the 1980's. Stainless New Model Super Blackhawk and PMC ammo. It was one case out of the box that split. A few years later I had a Hornady factory .44 mag. split, but I don't remember what gun that it was in. I think I remember reading that PMC had a few issues back then, then again maybe I didn't read it. The Hornady split surprised me more then the PMC split, but being open minded I have not bought either brand since. It is possible that the Ruger had an over size chamber but again it was only that one case. I doubt any damage was done to youre gun. Clean the chambers and the bore and have it checked by a smith. Have him mike the chambers also. That will give you peace of mind if needed. Get a different brand or brands of ammo and blast away.