D.B. Cooper
Member
- Joined
- Oct 2, 2016
- Messages
- 4,400
So I'm prepping some once-fired Barnes 243 Winchester cases. Lyman's and Barnes' manuals both say trim to length is 2.035. These case are all measuring 2.040-2.042. How critical is this to accuracy? What would be the negative impact to accuracy if I didn't trim them. (I don't have the tools for that.)
I've always thought the trim to length had more to do with case life. Every time the cartridge is fired, brass flows forward, creating a longer case but also thinning the case wall thickness every time. Eventually, the case mouth splits and you discard the case.
I've always thought the trim to length had more to do with case life. Every time the cartridge is fired, brass flows forward, creating a longer case but also thinning the case wall thickness every time. Eventually, the case mouth splits and you discard the case.