New ar15 won't go into battery

[Masterblaster]

I just finished putting together a 7.62x39 ar15 and can't get it to go boom. When I tried to chamber a round by pressing the bolt release and letting it fly it picked up the first round, but the bolt failed to snap onto the round and lock into battery. I tried Many times with same result. If I place a round in the chamber and try to forcefully close the bcg, the bolt wont snap onto the round much less close into battery.If I take the extractor out, it chambers a round just fine and the bolt closes into battery. It looks like the extractor is not lifting enough to allow the extractor to snap over the rim of the cartridge. The barrel is a melonite ice arms and bcg is tactical ambush nib. I don't have a headspace guage or any other 7.62 parts to swap and see what fixes it. Any ideas?


Thanks

 

[Aimless]

do have a little black or blue o-ring on your extractor spring? If so remove it. Those little O-rings are designed to increase the strength of the ejection as well as lengthen the extractor springs life span. These inserts can cause problems in new uppers with really stiff extractor springs. Remove it, shoot a few hundred rounds and then you should be able to put the o-ring back in and the gun will function just fine.



This is the o-ring, it will be black or blue in color.. it may even be "D" shaped. It will be around the spring in the extractor. Remove it and reinstall the extractor without the piece. Basically your extractor spring, being new is too stiff. Take the o-ring off and give it time to break in before re-installing the o-ring.

[Broken External Image]:

 

[Masterblaster]

There is no oring, but there is some sort of bushing inside the spring

 

[Aimless]

yeah that bushing is supposed to be there.

 

[Aimless]

It is possible your extractor is out of spec. With the rush on parts that happened all through 2013 there have been a lot of QC issues with manufactures who are just trying to get parts for their guns. Pictures of your extractor would help but it sounds like maybe a new extractor is in order. Extractors are pretty cheap and it pays to have a spare to two anyways. I would just order a new one from BCM.
http://www.bravocompanyusa.com/BCM-SOPMOD-Bolt-Upgrade-Rebuild-Kit-p/bcm bolt upgrade kit.htm

 

[Masterblaster]

Removed the bushing and it worked

 

[Wallace's]

Removed the bushing and it worked

Try getting a new extractor spring. Maybe they sent you one with an out of spec spring rate.

 

[Aimless]

What color was that spring insert? Black or blue? You can run the rifle without the spring insert but your spring will wear faster. You might want to pick up a new insert down the road or some new extractor springs.

 

[Kaotiktribe]

I have honestly never heard of either manufacturer of either part

 

[Aimless]

Try getting a new extractor spring. Maybe they sent you one with an out of spec spring rate.

It could even be as simple as the hole for the spring and insert was not milled deep enough causing too much tension on the extractor to function properly.

OP there are a number of things it could be and there are a number of fixes. My advice buy a replacement extractor kit complete with new springs, inserts and o-ring. This way here if you have another problem down the road you can always do a parts swap and hammer out any problems you might have. When I go to the range I have a spare parts kit in my bag so I can trouble shoot on the fly.