I would strongly advise against opening up the gas port. Like Del said-dont shoot steel cased ammo in an AR. Brass casings will expand to the chamber and then shrink a touch, steel casings expand and are not as elastic. You will stick a case eventually.
Put at least 3-400 rounds through it before you pass any judgment on its reliability.
They are also a bit sensitive to your technique, make sure you are not "limp wristing" it.
Is this a factory complete pistol or a build? If it is factory whose is it?