BM1455 wrote on Dec 16
th, 2016 at 6:31pm:
Received my 200 today. . . They say Graf / 30-40 Krag on them. . .
I threw them into my Wilson case gauge and found that they were a little bit long in the shoulder. Since you should run them through the resize dies anyways as the necks are not perfectly round due to packaging, this gives you an opportunity to bump the shoulder back into speck. Contrast this to some old Winchester un-fired cases I have where they are quite a bit short in the case gauge right from the factory. No way to bump those forward so you just fire form those when you shoot them. So this stuff from Grafs should cause less stretching in the case head area than the Winchester or Remington brass when you fire it for the first time. . . So, maybe a good thing? Less wear on that part of the case with the Graf cases?
Comments?
Since you ask for comments, I have to say this perhaps shows a misunderstanding of case-stretch dynamics. In brief, unless the shoulder is far enough forward to hold the base of the cartridge firmly against the bolt face, shoulder position is immaterial to stretch with a
rimmed cartridge, since it is only any play (clearance) between bolt face, case rim, and barrel breech that will allow the case to stretch when its solid head moves back to the bolt while chamber pressure adheres the hollow case body to the chamber walls. Perhaps this explanation from Naramore will help -
(You need to Login to view media files and links)Same idea animated -
(You need to Login to view media files and links)If the rifle has generous headspace (or case rims are abnormally thin) and we want to prevent stretch and eventual separation, we need some mechanism to hold the case head firmly against the bolt face before firing - or to prevent the case body from adhering to the chamber. See
(You need to Login to view media files and links) for some ideas.
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KRAG BRASS (Read 22705 times)