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Posted: 5/7/2011 8:36:22 AM EDT
I am needing some help/advice on how to get my adams arms kit functioning properly. My setup is a DSA lower, Rock River upper, 11.5" barrel, Adams Arms carbine kit. After getting my tax stamp back I finally put my upper and lower together and when I went to charge the rifle and the bolt carrier group would bind in the buffer tube not allowing the rifle to charge. I tried switching stocks and buffer tubes with no luck. I should also mention that I purchased the upper used off an individual who said it ran flawlessly on his rifle. Has anyone had an issue with this or heard of this? I should also mention that I tried different uppers on my lower and it worked flawlessly. I hypothetically shot my upper on another lower(No binding) and after the 23rd round it bent the Piston Op Rod. ($115.00 to replace from Adams Arms) I am at a loss as to what the problem may be.
Thanks, Chris |
| Seems like you went through almost all the process of elimination to trouble shoot your problem but it sounds like you have an out of spec upper or perhaps a damaged upper which would bind up your BCG causing your op rod to bend, it takes a lot of force to bend that up rod. Be safe and take it into a gun smith to give it a look over unless you have another upper you can switch out, not worth having a mis-fire or upper blow up on you while you shoot it. Good luck and post back when you do find the cause of it. |
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My Adams Arms upper (16" barrel) has s similar problem on one of my lowers. The BCG binds in the buffer tube. Most probable cause is a slightly tilted buffer tube. It doesn't have to be much either. The anti tilt skis substantially add to the diameter of the bolt carrier. A regular DI bolt carrier has a lot more wiggle room than the bolt carriers of these piston systems.
To give a quick check you can do one of two things. Try another lower. You should be able to feel the difference just by manually cycling the bolt. Another thing to do would be to loosen up the buffer tube so it has a little play. Does manual cycling now feel better? You may be experiencing a built up of specs. Nothing is out of spec. They just don't mesh properly. If this is so, I point to the new design as the root cause as it is the one changing the rules so to speak. |
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