Finally got a chance to run some rounds through it today. Started out with 50 rds of Winchester 124 grain NATO, followed by 200 rds of cheap federal champion 115 grain Ammo. It rain flawlessly through the first 250. The last 50, I went back to the NATO rds and had one failure to return to battery. I also had 2-3 light primer strikes in that last 50. Going to clean it up real good and go shoot it again soon. I know those NATO rds sometimes have hard primers so I don’t know if it would be an ammo issue or a gun issue. It’s a early run (Jan 2018) gun so it might need to go back to Sig
Try some American Eagle in order to rule out the hard primer issue.