scattershot
Member
In my humble opinion, your problem is seating depth, and is related to the leade in the rifling. Some pistols have more taper leading into the rifled portion of the bore, and if it's short, some rounds will not chamber. I had a Kahr that way. It wasn't the chamber itself, but the abrupt leade that was the problem. A few thousandths deeper seating or a different bullet profile will fix it.
good luck!
good luck!