morcey2
Member
This has to do with the rifle mentioned in this thread:
http://www.thehighroad.org/showthread.php?t=730315
It's a Dominican Republic mauser with the original 7x57 21" barrel. It seems that it has a very tight chamber headspace-wise, but has a very oversized throat/neck clearance. All of the cases in question were from factory Remington 140 grain Core Lokt loads, not reloads of any kind. I fired all 20 of them yesterday and was resizing them today. The first thing I noticed was how difficult the resizing was. So, I mic'd the outside of the necks on the 17 that I hadn't resized yet and they all measured at 0.329" to 0.330" outside diameter. I measured a couple that had been fired in my other 7x57, a 1910 Mexican, and hadn't been resized. They measured 0.324"-ish. After I resized the ones fired yesterday, they measured 0.318", but would probably expand slightly with a seated bullet.
Also, I had 3 necks split on resizing, something I've never seen happen on once-fired brass in anything else.
Note: I tried searching to find something on this, but everything keeps coming up with expander dies or neck-turning stuff.
So, is there a spec or rule-of-thumb on when case neck expansion is excessive? The split necks are telling me that I've probably hit that limit on this rifle so it'll probably be rebarrelled, which is what I was planning on when I bought it anyway.
Thought?
Matt
http://www.thehighroad.org/showthread.php?t=730315
It's a Dominican Republic mauser with the original 7x57 21" barrel. It seems that it has a very tight chamber headspace-wise, but has a very oversized throat/neck clearance. All of the cases in question were from factory Remington 140 grain Core Lokt loads, not reloads of any kind. I fired all 20 of them yesterday and was resizing them today. The first thing I noticed was how difficult the resizing was. So, I mic'd the outside of the necks on the 17 that I hadn't resized yet and they all measured at 0.329" to 0.330" outside diameter. I measured a couple that had been fired in my other 7x57, a 1910 Mexican, and hadn't been resized. They measured 0.324"-ish. After I resized the ones fired yesterday, they measured 0.318", but would probably expand slightly with a seated bullet.
Also, I had 3 necks split on resizing, something I've never seen happen on once-fired brass in anything else.
Note: I tried searching to find something on this, but everything keeps coming up with expander dies or neck-turning stuff.
So, is there a spec or rule-of-thumb on when case neck expansion is excessive? The split necks are telling me that I've probably hit that limit on this rifle so it'll probably be rebarrelled, which is what I was planning on when I bought it anyway.
Thought?
Matt