Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Try some name brand M193 ammo.
If still doing it, try a known good (used) BCG.
If still doing it, put upper on a known good complete lower.
If it is still short stroking, contact PSA customer service and send it in and let them repair it. Once you go pulling the gas block off, etc, you void the warranty on the complete upper you paid for.
Gas block could be misaligned as well, creating a gas issue. The travel of the bcg doesn’t have to go all the way to lock back position to eject and chamber another round. I’m guessing there is maybe a .25” of travel difference between being able to chamber the next round and being able to lock back.
You could try a lighter buffer, or remove a weight or two from your buffer to see if it locks back then.
If it comes to that, how does one disassemble a buffer? It looked like one piece to me, I didn't study it, though.