Quote:
|
I noticed that 1 out of 10 pieces of brass will not wind up with the shoulder bumped back as far as the others....
|
After several firings (in my own M1A), I see the same thing. Since I use a headspace gauge to do a quick look at cases after sizing, I'll occasionally see cases as much a 0.002" off what my target dimension is. Those I'll run back into the sizer and "bounce" against the top (case backed off a 1/4" and then bumped back fully up into the die) to fix.
I attribute this to different brass "spring" as the shoulder fire-hardens. Were I to be keeping these cases past the nominal 4-5 reloadings (for an M1A), I'd anneal and move on.