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Posted: 10/1/2011 11:50:37 PM EDT
| I got a new adams arms ultra light upper for my rock river arms lower. i have used three different kinds of mags and the gun isnt cycleing right. Sometimes I get 5 rounds off with out a failure but most of the time it is one round and I have to poll the charging handle to put a fresh round in the chamber or it trys to jam two rounds in the chamber. It was a mid lenght to midlenght switch and all of the mags have the same problem. I have adjusted the gas block settings and still the same problem. I dont know if it is the lower, upper or the buffer weight or spring. The gun worked just fine with di upper. I'm shooting blazer fmj ammo that worked for the old upper. Any suggestions on a fix? |
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Failures to eject problems are usually due to (in order), ammo, too heavy buffer weight, gas issues and failure of the extractor. Midlength gas systems are right on the edge of running properly due to dwell times in the barrel. basically your bolt is not going all the way back into battery unless it is the extractor, which usually takes over 10k rounds before that happens.
Good luch with getting your stick fixed. Fatkid |
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I switched ammo today, tried PMC, some really cheap stuff and some high end loads. Everything was a fail in all 3 different mags and 3 different buffer weights. It is short stroking but only about 75% of the time. So I'm calling Adams tomorrow...
It was really embarrassing being put to shame by a $600 bushy during a fun shoot and my buddy's today.... Thanks for the help. |
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Please explain exactly what is occuring. Are you having:
- Failure to extract (spent case stays in chamber which prevents a live round from being chambered). - Failure to Eject (spent case does not get ejected out of the gun - this usually causes a stovepipe or other issues). - Failure to Feed (the live round will not feed properly even if the chamber is empty). The possible causes and fix for each of these vary. |
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Quoted:
Please explain exactly what is occuring. Are you having: - Failure to extract (spent case stays in chamber which prevents a live round from being chambered). - Failure to Eject (spent case does not get ejected out of the gun - this usually causes a stovepipe or other issues). - Failure to Feed (the live round will not feed properly even if the chamber is empty). The possible causes and fix for each of these vary. It is a failure to feed, most of the time it will only feed the round 1/2 way in or not at all. Then other times it will cycle 2-6 rounds before there is a problem. |
| Call Adams Arms, the whole try different ammo thing is a waste of time, any quality upper should run any ammo from Remington to crappy Wolf. Adams Arms has great customer service they will help you trouble shoot it and you can send it back to have them look at it. |
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Quoted:
It is a failure to feed, most of the time it will only feed the round 1/2 way in or not at all. Then other times it will cycle 2-6 rounds before there is a problem. This sounds like it's short stroking, have you check the AA gas block? I had the same problem with an AA upper, and was using std carbine buffer, the problem was that the was block hex screw came loose and the gas block was moving, so it goes BANG BANG CLICK. When I found the problem, I re tighten the gas block, and blue loctited the hex screws. Never had any issue again. |
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I had the same problem when I was using Spike ST-T2 Buffer and Wolf ammo. I would get one or two shots and the fail to eject or feed. I change the spike buffer to the standard Carbine Buffer (3oz) and she works like a champ! i've been told that Admas designs their uppers to be run with a standard buffer, i had the same issue with Tula/Wolf. i left my Spikes T2 buffer alone and just started shooting better ammo, problem solved. |
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+1 to AA ... their customer service folks will get this thread's original poster's issue sorted pronto.
I have two Adams Arms mid-length piston systems bought new, and i am very pleased with both of them...no failures, so far. Each has cycled flawlessly while consuming several hundred rounds of LakeCity M855 ammo fed from Pmags. One upper is a complete EVO ultra-lite, and the other i built from stripped using AA's retrofit kit. The EVO is mated to a POF Gen2 lower, and the other is a billet Mega/Mega pairing. Both lower tubes are filled with a Tubbs spring and Spikes ST-T2 buffer. Both uppers and their barrels have M4 feed ramps. I position pistons at 12 o'clock...i.e., normal. ~~ |
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Quoted:
I got a new adams arms ultra light upper for my rock river arms lower. i have used three different kinds of mags and the gun isnt cycleing right. Sometimes I get 5 rounds off with out a failure but most of the time it is one round and I have to poll the charging handle to put a fresh round in the chamber or it trys to jam two rounds in the chamber. It was a mid lenght to midlenght switch and all of the mags have the same problem. I have adjusted the gas block settings and still the same problem. I dont know if it is the lower, upper or the buffer weight or spring. The gun worked just fine with di upper. I'm shooting blazer fmj ammo that worked for the old upper. Any suggestions on a fix? If the upper is new I would oil down the bolt carrier and brush off the bolt. Since it's new it may be a little tight. It will get better after you oil it. I had the same problem with mine and now it runs like a champ. And n Ow I have once 4000 rounds down range with no problems and that's with a few tactical courses |
| Sounds like gasblock is out of alignment or something mechanically slowing down velocity of BCG causing short stroking. AA will get you fixed right up though. Ammo isn't the problem. I doubt your buffer is causing it too. Just guessing though. Hard to say without seeing it. |
| I'd like to know AA's response too, I have a mid length AA upper that I have gotten to run twice (bought it in Dec while on leave) and I was having the same issues, the bullet nose seemed to get jammed into the feed ramps. I greased them a bit while shooting and it seemed to ease the issue but when I am on leave I want to shoot not have feed issues. |
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i have one of the first 5.45's that shipped. i had short stroking and some failure to fire. i did use the extra hammer spring that came with the upper and it didn't matter.
I called them up and mailed it back (on my dime  ) and i included some of my surplus ammo. i think it was 2 or 3 weeks it came back and has been 100%. they never said what was wrong and i don't really care as long as they did what neded to be done.
so i have enough faith in AA that my second 5.45 upper from midway (cost $525 after the $75 off dicount) is on the ups truck today to my house. on my cav15 lowers and c-more dots, it is a lite fast pointing package. |
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They didn't say what was wrong with it. When I talked to the guy from AA I was at work and couldn't spend that much time on the phone. He did ask if I had the gas block apart so I'm thinking that the problems was there. I know it works now and it shoots very nice. It was also fun to pull the bolt out and toss it to a friend after 30 rounds.
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