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Old 01-22-2010, 09:56 PM
Thomas_H Thomas_H is offline
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Personally, I'm starting to think that the failure to feed issues and the OOB discharges are connected. And in my opinion, the failure to feed issues are related to magazine geometry (feed angle, height in relation to bolt and chamber etc). The theory that's starting to develop in my mind is that the misfeed is distorting the cartridge (specificly how the bullet is crimped into the case) enough that on occasion it keeps the cartridge from chambering properly. This could account for some of the sub par accuracy that this "match grade" barrel provides.

There are a few other possibilities that I'm considering.
1. Bolt to carrier rail interface out of spec. If the rails are not parrellel it could induce enough drag to keep the round from chambering properly. On the other end of the spectrum, if the bolt is too loose in the rails, it's possible for the bolt to close off center causing the bolt face itself to crimp the rim and ignite the primer.

2. It's possible that the chamber is out of spec or on the tight end of the SAAMI spec. But seeing how the rifle seems to take stingers and some of the other long case hyper velocity rounds, I don't think this is the case.

3. Improper headspace not allowing bolt to go into battery or too much headspace resulting in an unsupported portion of the cartridge. This is a very real possibility.

I had another idea before I started this reply, but I can't remember what it was.

I think a somewhat reasonable test for the failure to feed theory would be to pause firing between rounds, inspect the rifle to make sure the the bolt is fully in battery. Then carefully eject the round to inspect the bullet to case fit to make sure it is still true and not cock-eyed.

As for the headspace issue, it should be pretty easy to tell if it's too tight. The bolt would never fully be in battery with a round chambered. Checking if there is too much headspace is a little more difficult. I'm not sure how you would actually measure it.
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