+1 on steel case ammo junking up an otherwise perfect gun. Many years ago I had an AR that always gave me extraction/ejection/cycling issues. Turns out when I quit trying to run the steel case stuff all of my problems magically disappeared. Needless to say, I now reserve the steel stuff to use in AK rifles.

But, do what you wish as it is your weapon. Over-gassing an AR by making the gas port too large will cause issues as well. If the chamber isn't chrome lined i would recommend doing some serious polishing of the chamber to start with and see if that helps.