I've used this flat for all my builds (Romanian, East German, Polish) without any problems. I prefer this flat without trunnion holes pre-punched because I can get a more accurate trunnion location. With a dremel, I used a diamond wheel point to open up the 5 trigger guard rivet holes (just a hair) for better fitment of the AKB rivets. Axis pin holes reamed perfectly. Safety and magazine fits snug. I highly recommend this flat and will continue to use it for future builds.