I have been measuring 1x fired hulls from my Marlin 512 and comparing them to new. Now it is time for a chamber cast. I know most are trying to make sure their slugs are tight in the bore, but what about a loaded cartridge being tight (centered) in the chamber? My thinking is a lose cartridge equals slug out of alignment with the bore.
I have several "fixes" to try but will test before posting about them.
BB