I saw that you are using A-Meric ammo. I did a search and found at least 2 sites that did not favor that ammo.
Here is a quote:
NOTE - The last ammunition on this list (A-Merc) shows very unusual results. It was the last in a test series but the chronograph was set-up exactly as for preceeding tests, although the light level had dropped. It cycled the gun, tho hard to believe! The odd thing is that the five shot string shows quite a small spread, making the readings seem viable, despite absurd low velocity. In time it is hoped to run a further test on this ammo' to see if it is truly as low as it seems from this test! Either way, it seems very poor quality indeed, with deformed (plated) bullets common.
Ammo ReviewSo, it seems that it may be your ammo causing the problem. If it is out of spec, then you are risking your life, rifle, or other parts of your anatomy. Do not use crap for ammo in an AR. From all that I have read, ARs are touchy with regards to ammo types.
Once you get the round out of the chamber, pay $$ and get some good ammo to test your rifle with. Also, find out if it has a .223 Rem chamber or 5.56 NATO chamber. .233 Rem chambers are smaller. Read the FAQ. After you have tested with quality ammo, and you still have a problem, then contact RRA and ask them for help.
As an example, I shoot Wolf ammo in my AK all the time, but I don't think I would ever shoot it in my AR. AKs are sloppy and loose, not intended to be tack drivers.