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Posted: 10/25/2010 9:06:14 PM EDT
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Took several rifles out today that I had not shot yet. Two of the rifles kept having malfunctions––-the same function––-and this was the first time both had been shot.
Rifle 1––S&W 5.45x3916" upper mated to a S&W lower w/orange hammer spring. Ammo was Silver Bear. Rifle 2––M&A Parts 7.62x39 10.5" mated to a SBR lower. Ammo was Wolf "black box". Both rifles were having the same malfunctions. The 7.62x39 upper fired the first three rounds fine. A shell case did not extract and a new round was half stripped from mag jamming the rifle. This was a PIA to clear, Locked back bolt and cleared the mag and extar round. The spent casing was still fully in the chamber. Released the bolt. Bolt did not close all the way––just barely open. Tried the charging handle and the BGC is stuck. I mean jammed. Will not move forward or back. I ended up having to hammer open the bolt which also extracted the shell. Reloaded the rifle. Fired the first shot and the same jam again. The 5.45 upper went though about 80 rounds or so before having the same above malfuncton. Again, had to hammer open the BCG. Only diff was went though about another mag before it malfunctioned again. I have not inspected the rifles/BCG fully yet. I well oiled, and I mean well, the 7.62x39 upper before I tried it for the last time with the same results. All rounds fired when the BCG would fully close so there did not seem to be an issue with the hammer spring or the firing pin. The mags aso seemed to be working fine. I looked over several threads here and so far it seems I need to check or do the following. Check and maybe install an enhanced extractor spring/ring in the bolt. Next would to be inspect and maybe polish the chambers. ANYBODY HAVE ANY OTHER IDEAS OR THINGS TO LOOK AT? Thanks |
| I had a Yankee hill 556 barrel that did something similar for about the first 50-100 rounds.. after the chamber broke in no problems.. the problem i was having was when you fired a round, the next round would load, or partially load, and then you could not extract it without firing it out on an empty mag. Thats assuming it did chamber... if it partially loiaded it was a mess2-3 mags later and it was a dream to shoot! |
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Rough/bad/dirty chamber. Probably a little of all three.
Steel cases have less forgiveness than brass. At least you'll get practice with proper removal of stuck cases. [I prefer to tap the case out from the muzzle with a cleaning rod IF the extractor has already slipped off the rim. If the extractor is still engaged then "pull down on the charging handle while slamming the butt on a surface" actually works, eventually.] There are a lot of unpublished tricks for home-honing chambers. |
| okay you stated that the guns were unfired.... so you should be breaking them in with some good ammo, and your chamber will "break in". if your shooting steel cased stuff, there have been instances of the lacquer getting hot and sticking... the lacquer is supposed to be a lubricant on some ammo.. I don't shoot the crap... there is no savings when all you have is problems! |
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I cleaned both rifles today. I checked the extractor on both and the seem fine. I'll them alone for now.
The 5.45x39 upper––-To be honest I do not recall if I had cleaned this rifle since I bought. This may have been my first issue. This was Silver Bear ammo in the silver cases. I do not think this stuff has laquer coating on it. Who makes brass 5.45x39 ammo? I've seen Hornady makes some but I thought it was steal case also. Still not sure what to try on this one yet. Maybe try it after know I gave the chamber a good cleaning. The 7.62x39 upper––-I do have some new AE brass ammo to try on this rifle but I think it needs some work first. The first thing I noted after cleaning the BCG was the bolt seemed very tight inside the carrier. All my other ARs bolt will move freely when well oiled after cleaning while in the carrier. Not sure what meybe causing this issue but I have a spare BC that I will try the bolt in. Any other thoughts on this? I put a Wolf round back in the chamber and it would not fall back out on its own like my 5.56 uppers do. I cleaned the chamber. I tried the round again and it seemd to slide in and out better but still not as easy. I put the BGC back in and chambered a round. Well again the BGC got stuck. Had to hammer it open again. Based upon this I think there is a chamber issue. Now where do I start first? Send it back to Model1sales? How do I check the chamber for sizing? Is there an easy way to do it or do I need head gauges? Should I just try polishing the chamber? Thanks |
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