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12/8/2011 11:50:49 AM EDT
I’m having a problem with a brand new Adams Arms 16in upper. I just got the thing a few weeks ago, and was able to get it out to the range a few times since then. It is having trouble picking up and chambering rounds. It will fire, then it will do 1 of 2 things.

1.Either the bolt will close and no round will be picked up. Sometimes gouging the hell out of the case.
or
2.It won’t load the round straight and it will get jammed.

This happens every time with 1 exception. The gun shoots Brown bear lacquered hollow points just fine. It won’t shoot wolf black box or federal premium.

I’ve tried it with Magpul Pmags, colt mags, and bushmaster mags.
I’ve also tried it with a Colt lower, and an Umbrella lower.

I’m no expert by any means, and I’m out of ideas. I just wanted to see if anyone had any ideas before I called the company.
12/8/2011 12:04:25 PM EDT
[#1]
One method to narrow down what it could be:
Crack your rifle open, remove the bolt, take a round and by hand run it up the feed ramp in the reciever into the chamber ,see if there is a lip or gap between the reciever and the barrel feed ramp, if there is you should feel it by the nose of the round catching on it then you know its a feed ramp issue.

Gas issue: load 1 round in a magazine fire it; bolt should lock back, if not you know its a gas issue.
12/10/2011 12:06:59 PM EDT
[#2]
anyone else? I posted in the AA forum as well.
12/10/2011 6:41:23 PM EDT
[#3]
this happen to me the first time i shot my AA, when i was breaking the barrel in. it had a feeding issue as well (i think 4 times) out of 100 rounds that day where it didn't load the round, it just gouged the shit out of it, bad. i loaded one round at a time for 20 rounds, cleaning the barrel after every round. then 3 rounds at a time for 30rds, cleaning the barrel after every 3 rounds, then 5 rounds, for the rest of the ammo left, cleaning the barrel after every 5 rounds. i figured it was just the barrel being broke in, feeder ramps/ bolt wearing its self into the upper to slide more freely with less resistance from being brand new ....when i got home, i cleaned the entire rifle and hit all moving piston/ bolt parts with a very light Remington dry lube. i had the rainier arms XTC compensator pinned on and it has feed fine ever sense. even with rapid firing/ mag drops... so i don't know if the comp had anything to do with it, or if it was just a fluke thing being a new unfired barrel and bolt, or what. iv cycled hundreds of rounds since that first day and not a single hick-up.

hope that helps some
12/10/2011 8:06:21 PM EDT
[#4]
If it a complete upper, i would say that you need a lighter buffer/spring.  if it was assembled by someone not AA, check the gas port for correct size
12/11/2011 3:32:14 AM EDT
[#5]
I would brush off the bolt really well with a brush and oil the crap out of the bolt carrier for a few rounds until she breaks in.

I had the same problem with my AA upper and that is what I did to solve the problem. Since then I shot a few thousand rounds with no issues
12/11/2011 6:47:06 AM EDT
[#6]
Well, It looks like I'll try stripping it, cleaning it, and trying to break it in with the brown bear for a few hundred rounds before I send it away. We'll see how it goes. Thanks for the replies.
12/11/2011 7:08:10 AM EDT
[#7]
If you have the clamp on gas block, rather than the pin on gas block, check to see if the gas block is a little loose or if it's sliding forward. That shouldn't happen with the pin on block, but it's possible with the clamp on. This would cause short stroking.
12/11/2011 2:17:12 PM EDT
[#8]
Any chance the gas setting was set for suppressed fire?

Posted Via AR15.Com Mobile
12/11/2011 2:22:33 PM EDT
[#9]
Quoted:
Any chance the gas setting was set for suppressed fire?

Posted Via AR15.Com Mobile


I checked that. Would have been too easy.
12/13/2011 5:27:26 AM EDT
[#10]
someone posted this response to my question in the Adams Arms forum. Let me know what you think.

"Slowly work your BGC. Do you feel any binding as it pulls back? It should feel no different than any other AR. I would try the Adams Arms upper on another lower before I did anything else.

I have an Adams Arms upper and it will not work on my Sendra lower. I have traced it to a very, very slight tilt in the buffer tube. Because the skis on the rear of Adams Arms bolt carrier add quite a bit of vertical height of the carrier, it will bind slightly and cause a short stroke if the tube has too much any tilt to it. If the tube is loose is works fine. There is nothing wrong with my Sendra lower as any original style upper works fine on it. I even tried a completely buffer tube and stock assembly on my Sendra lower and it would not cycle properly.

I don't think that there is anyting wrong with my Adams Arms upper either as it works fine on my other lowers. It is simply a tolerance build up for that particular combination of parts. "




My response to that.
"I can try what you said when I get home, but I don't have much experience with AR's. I had one DI AR that worked just fine. I sold it to finance my Adams Arms upper. As far as I'm concerned, if it works with one lower, but not another one, then it's garbage.
And like I said, it doesn't work with the Colt lower, or the Umbrella lower. I don't have a third one laying around to play with. "
12/13/2011 5:57:07 AM EDT
[#11]
Just bought a 16" midlength AA from midway and took it to the range. The first 2 magazines had the same problem you described. after that and 300 rounds no FTF problems. i think it just needed to be broken in.
12/13/2011 10:24:33 AM EDT
[#12]
Were you able to get it to shoot a certain kind of ammo first and break it in with that?
12/18/2011 12:09:49 AM EDT
[#13]
I was just wondering, does the front of the hammer of your lower have notch cut out on it?
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