Very wise to experiment with a variety of common cartridges to determine the frequency and significance of the issue. You can also use my low-brow, rubber-band under the shell rim. If it were indeed deep chamber rims, carefully applied JB Weld and a properly lubed case could be a remedy. Something I would do, but that's me.(Based on firing pins protruding correctly) Testing with commonly available ammunition is the first test.
I might add that, assuming you are not using any reloads and your machine is smashing the rims too flat.
Last edited by liverwort; 06/07/25 12:17 PM.
