That's a lot of question. Let me see if I can answer most of them.
I shoot off a bench. I don't make my own bullets. I use conical like T/C Maxi Ball 370 and hornady Great Plains 385's. I don't change powder brands. Elephant powder is what I use.
Weather report:
sunny, slight breeze, 58 degree, Humidity level: ?
When I clean it. None of the patches I use have any tears.
I'm not sure what's going on, but I'm thinking it more the rifle being the problem. More range time is needed to make sure.
- FallingCrows