I have a 28 Nosler built on a Defiance Deviant Hunter action with a 26 inch Proof Sendero barrel and an APA brake and an AG Customs Carbon Fiber stock fully bedded. I did a ladder test with Reloader 33 and I came up with a node at 81.7 grains behind the 195 EOL giving me 2984 fps average. I then performed the Berger bullet seating test and .020 off the lands shoots .4 Moa for me. I finally got a chance to get this thing out to 900 yards and missed my first shot but hit the next three in a row. I then checked my drops out to 700 yards against my Sig kilo 2400 rangefinder and everything seemed pretty good. Next time out I took a 600 yard shot and missed even though everything felt perfect. So the next day I shot a group and the first shot was 1.5 inches high at a hundred yards and the next two were touching right in the center of the bullseye. Tried the same thing the next day and my first shot was an inch low and the next two were a bughole dead center of the bullseye again. I obviously have a cold-bore shot problem and I've heard that hbn coating can solve this problem. I'm just wondering how much do I need to adjust my load by to make up for the loss of FPS using hbn? Do I still use 81.7 grains of reloader 33 or do I need to adjust my charge to get back to that same node at 2980 FPS? Also if anyone has any other ideas what could be causing this please feel free to chime in. The gun was built by proof research and shoots lights out after the first shot.