Home Forums Hunting & Shooting Ask The Gunwriters Tight chamber,fast barrel?

I have a 7wsm that was built with a Brux barrel and custom reamer. When I was loading R-22 and 162 amax’s,I would get 3000 FPS 2 grains shy of max book load. I tried R-26 to max load of 3170 and am almost 4grains shy of max. This is using magneto speed that is consistent with other calibers. So what does the consensus say?