I have a 10.5" ar pistol im having trouble getting to cycle, it is not ejecting or reloading, i can manually eject and it will grab the casing and reload another round fine. something Gas related i assume, but how can i trouble shoot what the deal is and what is happening. ive built a few ar's, but never built or tore into an upper, so not sure where to begin.... upper is pretty new, only maybe a hundred rounds thru it, was operating flawless until now. Originally i thought it was a lower issue, as i bought one of the folders recently and put on this upper, and that is when it first happened. but since i have switched that lower to a different upper and it operates fine. Just something going on with this upper.
tia
-Mike
tia
-Mike