Well, one of the rifles that this happened in is my Cooper Phoenix in 6.5 X 47L. I actually got to ignoring it after a while and just kept going 12-14 cycles on the brass. No annealing, just standard prep. I don't think it's causing any harm other than perhaps shortened case life. Anyway, what defines an oversized chamber? How many thousandths in diameter over a SAMMI spec?
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- Thread starter SammySTW
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milo-2
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The case I was referencing was around .008" over a friends fired brass. Cheytac case. I have seen brass Roll, where it looks cracked at the base of a case from cases being to large in diameter. But, that may mean the chamber is a little big, but also that the die may be undersized for the application. In this case, having a custom die made would eliminate most of it. One more But though, it becomes an added expense and dimension that you never signed on for.
The brass was from Gunwerks factory ammo, that was fired once out of the box. It's my friend's gun, he bought a couple boxes of ammo, shot it and gave me the brass. It looked normal after firing, cleaned it with a hornady sonic cleaner and it looked just like they always do. Sizing them was considerably harder than normal, maybe just because I didn't let the lube dry properly?
They were fired in my friend's custom rifle, 700 action with a Proof carbon barrel. He hasn't said anything about feeding trouble, and I've never shot the gun myself.
It has been suggested the 308 W/7.62 NATO machine gun barrel has an over sized chamber, problem, I have asked if there was a member on any forum that had a 7.62 NATO machine gun barrel; no one raised a hand. If there was someone that had one I wonder how many years will it take for them to figure a way to measure the diameter of the chamber. I make datums, I save datums and I have been know to purchase datums; without exception reloaders believe my datums are a joke.
No problem, we have decided things that are obvious to me are vague to others reloaders. A friend built some very accurate rifles; he used machine gun barrels. And then one day he called, he said he had a complaint, seems one of his customers complained about about the fired cases. He asked me if I knew what it was about. I told him he sold a rifle to an Internet reloader; I asked him about accuracy. He said the accuracy was outstanding.
I boxed up a few tools and went for a visit. When finished the new owner of the very fine rifle was happy; accuracy did not improve and now he is using L.C. national match cases, we formed 200 cases.
F. Guffey
I have fired cases that look like your cases, I have scribed cases at the case body/shoulder juncture to determine what happens to the case when fired and or sized. It is obvious to me reloaders can not move the shoulder back, I have scribed my cases when determining what happens to the case when sized and when fired. And then there are 'bumpers',
I understand your cases have taken on an appearance that bothers everyone, I will promise you do not have a tool that has the ability to measure the high and lows that appear to be rings. I had a Pratt & Whitney electronic gage that measured .000005", I removed the electronics because there was nothing I do that required that precision. And now the gage is one smooth running height gage.
F. Guffey
try Dillon's lube it is a great lube and try a different die
