....Or reem the chamber
Having a set of progressive dies made, so that you can draw them to a slightly smaller diameter might be a fun project, but it’s not homeowner type stuff.
CZ, would you really consider altering a gun to fit someone elses used brass?
If the brass only goes half way in the chamber, then it is likely the thinner wall that's hanging up. At the least, maybe put some calipers on the brass that work correctly, and the bulged brass, maybe do the sharpie low budget dykem, if the markings don't show without it. The expanded brass is probably not at the head, if similar brass can fully chamber, likely the thin wall would have expanded.