Out of my home built piston driven ar with a Satern 1-6 22in. The factory feds 75 gr grouped very well and at 400 were more accurate than the 90gr.
But, im way out of practice shooting so TIFWIW
I can't speak to its performance in a gas gun but I shoot the 78gr TSX in a bolt gun. They shoot really well and at an avg of 2707FPS in a new 18" barrel with an SD of 10.