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Post by TMan on Feb 16, 2006 22:00:56 GMT -5
I had a little problem at the range today: something small went down inside my shirt. Curiosity got the best of me. It was the primer. I looked at the brass, and there it was, a cartridge without a primer.
Okay, so I then picked up all my brass and found one that the primer was part way out of the cartridge, and another had black stuff all around the primer.
The rest of the fired brass looked normal.
What gives? I've never had this problem before. This is a new case of S&B 7.62x39 ammo. Is it an ammo problem, or do I have a problem with the gun, like too much headspace or something.
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Post by Callahan on Feb 17, 2006 10:07:28 GMT -5
Sounds like a bad batch of ammo. If it were a headspace problem I would imagine all the rounds would have looked the same. I've heard S&B is dirty ammo but I don't recall any problems with functioning. Sounds like bad primers. Maybe you should contact the maker and provide the lot number. They may have had other reports of problems. Maybe you can get some freebie ammo in the process...
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Post by 5ontarget on Feb 17, 2006 14:12:15 GMT -5
I would think this is more related to a bad batch of ammo rather than the gun. I don't think this is a headspace issue. Too much headspace can cause case stretching, case rupture and leaking of the gasses. When the powder is ignited the base of the cartridge can move back while the sides of the case stick to the walls of the chamber. As a result the case can separate and rupture. Or the bolt is difficult to open.
Too little headspace makes closing the bolt and possibly chambering of the cartridge difficult/impossible. If the bolt is forced this can cause the bullet to be compressed further into the neck of the cartridge's case, causing an overpressure load. If fired, the end result could be similar to the excessive headspace situation.
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Post by "DoubleAction" on Feb 17, 2006 14:48:16 GMT -5
TMan; I'm only guessing that the primer might have not been fully seated, causing the firing pin to over penetrate and puncture the primer cap.
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Post by TA on Feb 17, 2006 19:08:03 GMT -5
It sounds like an ammo problem...or maybe the shooter? ;D Just kidding, my guess is ammo, not gun.
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Post by MLB on Feb 17, 2006 22:50:57 GMT -5
Could an overpressure cartridge cause the primer to blow out? It seems reasonable at first, but all of the KaBooms I've seen show ruptures near the (often unsuported) shoulder. Perhaps the breech prevents this from happening.
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Post by TMan on Feb 17, 2006 23:17:30 GMT -5
It didn't appear to be a firing pin penetration of the primer cap because the cap was pushed out of the cartridge. Perhaps they weren't seated properly.
Anyhow, I don't think I'll shoot anything from this case of ammo in this gun again. It was a relatively expensive gun compared to my other guns that shoot 7.63x39. In fact the cost of all the other guns (4) didn't equal what this one cost. Also, since it is no longer listed, and I'm not sure it was ever listed in their catalog, it might be difficult in getting parts for it.
I'm just glad the little primer cap went down inside my shirt or I probably never would have noticed. It ejects straight back at me, which is probably why it happened.
I'll shoot the rest of the case (880 rounds) in the AK-47 since I hate it anyhow.
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Post by TMan on Feb 18, 2006 8:09:51 GMT -5
I thought of something else last night, while I should have been sleeping.
Suppose I make a trip to Cabela's next week and pick up a die for 7.62x39. I could then remove the bullets, measure/weigh the powder, reduce the powder on any that are over the average and then re-seat the bullets.
Based on replies to my question, I'm thinking that the problem could be too much powder?
Does my "solution" make any sense or is it just a dumb idea.
(Weather outlook for the metroplex is not good this weekend so I'm not heading out to Cabala's for a couple of days).
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