Need Help

[rcromwell92]

I built the .308 AR seen in the video. Upon taking it out and shooting it with PMC Special. It was consistently failing to eject the spent casing. It caused double feeds and stove pipe failures consistently. The attach video shows my son shooting and the casing actually doing a complete 180 degree turn and stay in the rifle. Luckily it was the last round out of the mag so it locked to the rear. Can someone help and point me in the right direction on how to fix  the problem. The upper is an 18 in .308 complete with BCG from Daytona tactical. Any assistance is greatly appreciated... Thank you advance

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[98Z5V]

Get the specs on your recoil system up here first.  Internal length of the receiver extension - internal length, the depth of the tube - buffer length (and weight, if known), and the spring dimensions (relaxed length, coil count, wire diameter if possible).

Gotta start there.

Double feeds.  Just a word on those.  They are commonly misdiagnosed.  If you have a true double feed (two live rounds trying to enter the chamber at the same time), it is ALWAYS mag related.  Always.

[98Z5V]

In the video, the extractor let go of that spent case.  Bunch of possible causes for that (jacked up extractor or extractor spring, over gassed, etc.).

[rcromwell92]

96Z5V.. it wasnt a true double feed at all there were never to live rounds but it did continually load a live round fully into the chamber while trying to chamber the empty case as well.. as for all the specs I will have to either measure and weigh each piece and call daytona tactica...I know I got the carbine length ar10 /.308 buffer and buffer spring from brownells the tube is a standard mil spec carbine length 6 position. I accidentally put the ar15 spring in it and the bolt wouldnt lock to the rear so I made sure that the correct, buffer, and spring were in it before hand and then every few rounds I would get what was seen in the video

Im wondering if its the ammo causing under or gassing. I had a box of 150 grain fusion ammo and it only did it twice out of 20 rounds but the PMC did it every other round!!

 

 

[rcromwell92]

98Z5V could it be the ejector on the bolt?

[98Z5V]

Could be.  Broken ejector or ejector spring.  That doesn't account for the extractor letting the spent brass go before it's rearward, though.  Best thing to do is take the bolt completely apart and inspect it. 

[rcromwell92]

called the company I purchased the complete upper with BCG from (daytona tactical). They are shipping a brand new BCG and bolt no questions asked. In fact I got the tracking number the same day. (today) If that doesnt fix the problem, Im gonna put in an adjustable gas block and see if that fixes my issue!!! They said they test fired it with the exact same ammo I am having issue with. so the ammo isnt the problem. good to know. Thanks for the help I greatly appreciate it. 

[survivalshop]

6 hours ago, rcromwell92 said:

called the company I purchased the complete upper with BCG from (daytona tactical). They are shipping a brand new BCG and bolt no questions asked. In fact I got the tracking number the same day. (today) If that doesnt fix the problem, Im gonna put in an adjustable gas block and see if that fixes my issue!!! They said they test fired it with the exact same ammo I am having issue with. so the ammo isnt the problem. good to know. Thanks for the help I greatly appreciate it. 

 That's interesting . Makes one wonder . Good quick CS though .

[mineralman55]

This isn't the first time this issue has come up. The recoil system as the cause was already mentioned, but I suspect it is the extractor issue. There is something about these rifles that makes them especially sensitive to extractor design.

[jtallen83]

Similar issue cleared up for me by just swapping to an Armalite extractor spring kit.