Failure to eject or feed

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12 years 5 months ago #11663 by mckenna
Failure to eject or feed was created by mckenna
Salutations all, I have seen a couple of items on this subject but both were different from my issue. I built an AR10 using the MATEN billet upper & lower with a DPMS lower parts kit, Rainier Ultra match 24" barrel, DPMS BCG, milspec stock tube, Heavy Buffer's spring & buffer for AR10 carbine, Vltor collapsible stock and Battle Comp compensator. I shot it this weekend using Silver State 168gr OTM but it never would push the bolt back far enough to eject or feed. Never jammed and hand cycled fine it's just not pushing the bolt back. Primers are not flattening. To me it seems either not enough gas, too heavy a buffer or too stiff a spring or combination of all. I had checked the gas hole in the barrel and the gas block prior to installing and both were clean. I center marked the block and the barrel hole to make sure the alignment was correct as this is a bolt on gas block. So, before I remove the gas block and check that part I thought I would see if anyone had some insight into this dilemma. Thanks for any info

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12 years 5 months ago #11667 by LebbenB
Replied by LebbenB on topic Re: Failure to eject or feed
Sounds like short stroking to me. Check your gas tube as it enters the gas block for excess soot. Also, you're using a carbine heavy buffer and spring on a rifle length gas system. As you stated, that might also have something to do with it.

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12 years 5 months ago #11671 by mckenna
Replied by mckenna on topic Re: Failure to eject or feed
Thanks for the reply. It is definitely short stroking. I think that I'm going to pull the gas block and make sure the dimension to the port is the same as the dimension on the barrel. As well, I'm going to check to see that the gase tube port is lined up with the gas block port as someone told me they had an issue with that on a gun they built.

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12 years 5 months ago #11684 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re: Failure to eject or feed
To me, that is the problem with "building" a Rifle...although all the parts say compatible...sometimes they are not..
I would say from what you have stated...I would check the holes on both the Gasblock and the barrel...usually the port on the GB is larger than the one on the barrel...but if the port on the barrel is too small...it will not let enough gas into the tube...ArmaLite had a small issue one time with this...it is an easy fix..
but it needs to be done by a Machinist/gunsmith...for precise application...
I don't know the exact dimension of the barrel port needed, but I am sure you can find out what it is...as for the rest of it...I might also suspect the difference between the Carbine buffer system and Rifle system as well as the gas system, unless they are both Midlength...if not...there is your issue..but if you have a rifle length gas system with a carbine buffer...it shouldn't be short stroking..it would be hammering the bolt back much harder than needed...
BMS

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12 years 5 months ago #11686 by mckenna
Replied by mckenna on topic Re: Failure to eject or feed
Thanks for the reply, I removed the gas block last night and you are correct, the hole in the block is larger than the hole in the barrel but both holes were clear and aligned. I think I may have found my problem though. I have the J&P Rifles adjustable gas block and when I installed it I really didn't want to drill the hole into the tube for the adjusting screw. So, thinking since I didn't drill the hole in the tube I could leave the adjusting screw out. But, it may just be that gas is escaping through that hole. I re-installed the block and tube and the adjusting screw with some blue loctite. So, it will be back to the range tomorrow to see if that makes any different. I'm going to take a standard AR buffer & spring to try if it still won't blow back.

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12 years 5 months ago #11711 by mckenna
Replied by mckenna on topic Re: Failure to eject or feed
I want to thank the gentlemen that responded to my post. As I said in my last response that I had noticed that I had not installed the screw in the adjustable gas block because I had not drilled the hole required in the gas tube to use this function. I did install the screw with some loctite and just lightly snugged it tight and the weapon functioned perfectly. Evidently gas was able to escape even though I had not drilled a hole in the tube. Thanks again for your responses.

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12 years 5 months ago #11714 by BUILDING MY SASS
Replied by BUILDING MY SASS on topic Re: Failure to eject or feed
Glad to hear you are up and running.
How about a Pic of it it.... :woohoo:
BMS

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