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AR-15 issues, rds getting wedged between bolt and barrel

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Input requested...

I have put roughly 500-600 rds through my AR and have had this issue about a dozen times. The rounds simply get wedged at an angle between the bolt and barrel. Normally this requires me to breakdown the AR (remove upper from lower completely) and force the bolt carrier away from the barrel and then the round simply ejects. I have tried new Magpul 10rd mags as well as older pre-ban 30rd ones as well. I'm using only new 5.56 ammo, and have lubricated the heck out of the gun (originally thinking it was a lube issue).

Has anyone seen this before? Had it fixed? Thoughts? Theories?

Thanks in advance.
 

Mike-Mike

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Input requested...

I have put roughly 500-600 rds through my AR and have had this issue about a dozen times. The rounds simply get wedged at an angle between the bolt and barrel. Normally this requires me to breakdown the AR (remove upper from lower completely) and force the bolt carrier away from the barrel and then the round simply ejects. I have tried new Magpul 10rd mags as well as older pre-ban 30rd ones as well. I'm using only new 5.56 ammo, and have lubricated the heck out of the gun (originally thinking it was a lube issue).

Has anyone seen this before? Had it fixed? Thoughts? Theories?

Thanks in advance.

How can you take the upper off if the bolt isn't in the forward position?
 
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How can you take the upper off if the bolt isn't in the forward position?

You pull both pins.

Issue is most likely your feed ramps are not in spec or aligned properly, causing rounds to "jump".

m4ramps.jpg
 

Mike-Mike

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You pull both pins.

The hammer prevents the upper from sliding off forward and the bolt (halfway between stock and upper receiver) prevents you from lifting it up.

Well either way, I think you are correct and the issue is most likely with the feed ramps.
 
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When this happens, is the bolt behind the jammed round, or on top of it?

The bolt stays behind the round.

I did an inspection and it appears to be closer to the image in the upper right corner. That said, I did a thorough cleaning of the ramps with qtips and CLP. I'll report findings mid-next week.
 

mac1911

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Amy chance of over lube..... are your mags good. I know you tested them but are they good. Mag lips can wear or bend and the round will "jump " instead of being stripped off by bolt. Try a known good mag.
 
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Amy chance of over lube..... are your mags good. I know you tested them but are they good. Mag lips can wear or bend and the round will "jump " instead of being stripped off by bolt. Try a known good mag.

Over lube is possible, although I've had this issue since the build (so perhaps its an issue with the original grease). The 10rd mags are new Magpul, and the 30 rd is a known good one borrowed.
 
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