I had one of those and the marking is not wrong. The one I had was a custom shop. You should be able to shoot 45LC’s in it, or at least that is what I have been told. Here is the other side of the coin. It is going to be just like shooting 44 Mag’s in a 45LC… you are going to be splitting cases.

I know that is not what you want to here, but the split cases is the exactly the same reason I traded my barrel several years ago to a dealer. It shot 410 slugs decent, just another thought.