Lol a band-aid, its over gas systems and running suppressed to keep from beating your gun to death! All gas guns will run smoother and more reliable when changing out ammo loads and running suppressor.
I have built plenty of x39 uppers and have found what works 100%. Diamondback barrels, black rifle arms complete bcg, standard ar-15 spring and h2 buffer, superlative arms adjustable Gasblock! Drill gas port to 2.80mm if you plan on running subsonic ammo suppressed if not leave it and just...