I've loaded with CCI 400 and Federal Gold Medal AR Match. I don't see a difference. The issue I encountered with my gas gun is the fast twist doesn't deliver accurate loads with short bullets. I swapped out the original barrel and the accuracy improved but it shoots MUCH better with longer bullets.

I shoot thousands of 223 from a bolt rifle using CCI 400 without issue. I know they're not ideal but they work every time.

The difference between genius and stupidity is that genius has its limits. Albert Einstein