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Discussion Starter · #1 ·
A friend of mine bought an AR10 that was built by an individual. He is experiencing a lot of jams. The rounds also have dents on the face of the rims. I thought it could be an over gassing issue, or possibly a head space problem, but I am not sure.

Hoping maybe somebody who knows more about these than me can help.

Thanks

0_IMG_20190802_142930.jpg
 

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Reloaded ammo or factory?
That primer looks pretty tough

One thing you may need to check is the ejector spring and plunger. I bet there’s too much spring or the plunger is binding up. The extractor and spring can give problems as well. If there’s two springs under the extractor......pitch the inner spring and run the outer.
 

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At first I was going to say the same as Ellis. However, I see what I call an ejector swipe on the case head. This is caused when the case is stuck in the chamber and can't rotate when the bolt does. The primers don't look flatten to me which would mean high chamber pressures. That tells me the chamber wall might be dirty or rough.

I would do what Ellis said first. IMO, the AR-10 doesn't need 2 extractor springs.

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At first I was going to say the same as Ellis. However, I see what I call an ejector swipe on the case head. This is caused when the case is stuck in the chamber and can't rotate when the bolt does. The primers don't look flatten to me which would mean high chamber pressures. That tells me the chamber wall might be dirty or rough.

I would do what Ellis said first. IMO, the AR-10 doesn't need 2 extractor springs.

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On mine......it did the same. The two fixes I mentioned stopped the brass damage. Cleaning the chamber,polishing it helped some but never really fixed it.
 

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Do what Ellis said then start looking at this.

I would say maybe way over gassed.
Over gassing videos. Over gassing for an AR10 is much like over gassing for an AR15 for the fixes. Might want to try a heavier buffer and spring first. Your friend may need an adjustable gas block given the severity.


search results
over gassed ar10 - YouTube


Checking AR10 Head Space
proper way
at home way
with the barrel already installed
search results
ar10 headspace - YouTube
 

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Discussion Starter · #7 ·
Wow. Thanks everybody! Going to pass along what Ellis said first. I am yet to see the rifle in person so I will bring a cleaning kit with me when I go check it out. Hopefully I can help him get this thing running smooth.
 

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Another thing to consider. Commercial 308 is hotter ammo than military 7.62 NATO.

After doing the extractor spring thingy and cleaning the chamber, I would try some LC or WCC 7.62 NATO ammo.


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