This happened yesterday..
Was adjusting hopup, at a 10x12" target ~60ft away.
It seemed like I had it setup perfectly, 3 shots dead nuts on...
Then:
psssst gas leak
Racked bolt back
Took mag out
Refilled mag
Released bolt
Inserted mag
pssst gas leak
Disassembled and found piston broken, no Idea how its possible. Now an NPAS is a forsho upgrade..