I bought a couple of complete (minus buffer tube, buffer and spring) Anderson lowers at a gun show recently. I was going to use them for a couple Ciener .22lr kits that I was finally going to put in a couple of unused complete uppers. I put everything together and the kit would fire fine once but would not reset the trigger. If I charged it again it would fire again. I then put the .22lr upper on another lower and it worked fine. I then put a .223 upper on the Anderson lower and it had the same problem so by process of elimination I figured out the problem with the two Anderson lowers.
When I remove the upper and work everything manually it seems to be working just fine, but clearly something is amiss. The only thing visual that is different is the hammer. On the lower that I know works, it is a black hammer with a rear-facing "claw." On the two Anderson lowers that aren't working, it is silver in color and no "claw." I did some research and one thread said to check the installation of the disconnector spring and the disconnector. I did this and they both appear to be installed correctly, using the "working" lower as a guide.
Any idea what would keep the trigger from resetting on a lower where the upper is known to function fine on another lower?
UPDATE: I did some more test firing. The hammer seems to be going too far back when it is set back by the cycling of the upper. The trigger issue is resolved by charging the bolt again or by turning the safety selector to "safe" and back to "fire" between each round. I'm sure something is just installed incorrectly but my lack of experience has me stumped as to what it might be.
When I remove the upper and work everything manually it seems to be working just fine, but clearly something is amiss. The only thing visual that is different is the hammer. On the lower that I know works, it is a black hammer with a rear-facing "claw." On the two Anderson lowers that aren't working, it is silver in color and no "claw." I did some research and one thread said to check the installation of the disconnector spring and the disconnector. I did this and they both appear to be installed correctly, using the "working" lower as a guide.
Any idea what would keep the trigger from resetting on a lower where the upper is known to function fine on another lower?
UPDATE: I did some more test firing. The hammer seems to be going too far back when it is set back by the cycling of the upper. The trigger issue is resolved by charging the bolt again or by turning the safety selector to "safe" and back to "fire" between each round. I'm sure something is just installed incorrectly but my lack of experience has me stumped as to what it might be.
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