One group of 0.8 inch @2817 fps. ES=12.4, SD=5.4. Acceptable accuracy, but good ES/SD. Was hoping for more speed though.
Have been a big fan of the 7MM Magnum for years. This load looks outstanding for long range hunting. With a low ES like that you may find that your accuracy at 300 is great!
What I noticed is that you are assuming that the chronograph is giving you accurate information. I would not assume that. What I would do is go to JBM and do a manual calculation of velocity. Set the scope at let's say 3" high at 100. Using the ballistic calculator fire the rifle at 300 and see what the drop is. For example, your BC=.456 for the 150 NBT. I did a calculation on that bullet with a temperature of 59F and 35 percent humidity at sea level. In order to get a a 250 yard zero at a velocity of 2817 you would set the scope 3" high at 100. Play with the numbers and set your elevation, temperature, humidity etc. into the calculator. You can get pretty close to actual velocity by measuring bullet drop at various distances. Besides it is fun!
JBM - Calculations - Trajectory
Personally I would forget the crimp and would not clean the rifle until accuracy drops off.