Was hoping someone can give me some guidance, I have a new 6 Gt proof pre fit barrel on impact 737 that I'm trying out. My brass, alpha ocd, has about 0.005 more Headspace after firing than my previous smith chambered barrel which was only 0.005 more than new brass. So basically I got 0.010 more over virgin brass with this proof pre fit. Is this to much? Will I ruin my brass? I got about 800 pieces of 1st fired alpha brass on previous barrel that I want to use. I normally full length re size with 0.002 shoulder bump.
6gt Headspace
- Thread starter Jarhead94
- Start date
Thanks. I was kinda leaning on just neck sizing on this 2nd firing on brass, already 0.005 under, and just letting it basically fire form again, then do my full length sizing 0.002 shoulder bump. I'm just hoping this won't over work my brass to cause any kind of case head separation.
The farther you go down the rabbit hole, the more you may want to buy a Go-Gage for your favorite cartridges, just a suggestion.
If you get a new chamber, you can determine the shoulder datum length by adding thin tape to the base of the gage. You will spend less time scratching your head.
Also, it is a good idea to learn to inspect all the lengths that matter to you, as well as learning to use a micrometer to inspect the critical diameters.
Take some numbers on a sample of brass that fits the chamber, then add tape to the base to see if the bolt will close without drama. A case is less stiff and "readable" than a Go-Gage, but it can work too.
It isn't as hard as it sounds. YMMV
If you get a new chamber, you can determine the shoulder datum length by adding thin tape to the base of the gage. You will spend less time scratching your head.
Also, it is a good idea to learn to inspect all the lengths that matter to you, as well as learning to use a micrometer to inspect the critical diameters.
Take some numbers on a sample of brass that fits the chamber, then add tape to the base to see if the bolt will close without drama. A case is less stiff and "readable" than a Go-Gage, but it can work too.
It isn't as hard as it sounds. YMMV
If you adjust the sizer not to bump the shoulder at all, running your “1x fired through the previous barrel brass” will move the shoulder forward a bit.
The question is how much is "a bit". I say either neck size or FL size with at least .001 bump.
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Depends on how much the die is squeezing the brass body. 1-few thousandths
The should only moves back one it’s made contact in the die, until then the shoulder squeezes forwards a smidge.
His brass is .005” shorter than his chamber. Why would you bump the shoulders of those cases .001”? If he sets his die not to bump the shoulders then the shoulders will prolly get popped forward .002-.003” which will produce .002” of clearance.
