captmoa


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captmoa
November 6, 2009, 02:39 AM
I'm wanting a bolt action for the 7.62x39. Reason is not part of the question. Have found a few: CZ, FN, Ruger, Remington and even a Enfield conversion. My question is: I heard that some manufacturers are using a .308 barrel instead of a .311 and could be over pressured by surplus fmj 7.62x39 rounds. Anyone heard of this? Thanks.

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R.W.Dale
November 6, 2009, 03:15 AM
FIRST OFF

None of the manufacturers you list use a .308" bore. In fact the ONLY production 7.62x39's that used a .308 bore were the very first run of ruger mini30's


SECOND

even If you had a x39 made with a .308" bore the .002" diffrence is NOT enough to cause any pressure problems whatsoever. And yes I have such a rifle

kanook
November 6, 2009, 08:23 AM
Welcome to THR

I believe Ruger still uses the .308 bore. The new Lyman 49th edition handbook agrees with this.

I have seen books be wrong before but I don't have a slug to prove otherwise.

Yes krochus I know you know a lot about the x39.

R.W.Dale
November 6, 2009, 01:08 PM
I believe Ruger still uses the .308 bore. The new Lyman 49th edition handbook agrees with this.

http://www.thehighroad.org/showpost.php?p=2776060&postcount=16

I'm a long-time, devoted, cast-bullet nut of the worst sort, and internal barrel dimensions can be critical in the cast-bullet game.

Therefore, when I obtained my stainless Ruger Model 77 bolt-action in 7.62x39, one of the priorities was to find out what the bore dimensions REALLY are. As mentioned earlier, the lead slug doesn't lie.

Are you ready? This 7.62x39 M77 Ruger bore has a groove diameter of .3105", definitely NOT a standard .308" barrel. It was slugged three times to be absolutely sure of the result.

It has now digested well over 150 separate and distinct cast-bullet recipes, ten rounds per combination,with bullets from 130 to 220 grains, all sized at .312". Powders ranged from Unique to IMR 4350, and decent results were obtained with quite a few of my loads.

kanook
November 6, 2009, 07:00 PM
See, I knew you knew somebody that slugged one. It's one of the reasons I'm gonna slug mine one of these days.

As we all know, all results will vary. Just makes a person wonder why the book does have a disclaimer in it about that and it's not true for all of them.

dakotasin
November 6, 2009, 08:29 PM
because it is a lot harder to over-pressure a 311 bore w/ 308 bullets than it is the other way around... they're just covering bases.

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