Great thread and thank you. I am having the same problem. BCG is not loading the next round. I have a STAG 22" barrel on Aero parts and Odin gas block.
What was the conclusion on everything here? From what I gathered:
1) The buffer spring was replaced with a weaker one, but that was only compensating for the undergas problem
2) the OP drilled out the barrel gas hole to .100, up from about .093.to 095 -Optimal for adjustable gas block, negates the need for the spring replaced in item 1 above.
3) Armalite gas tube was used which is a bit longer than a DPMS ?
4) Ejector problems, OP polished the parts and fixed that problem