I just returned from the range where I fired my .375 - .416 Rem with a 27.5" barrel. The range was 300 yards. Five shots with Hammer Sledgehammer 275 grainers. Each shot had one grain more than the previous round. Using Federal 215 Mag primers and Varget powder, I started with 76 grains and went to 81 grains where there was a slightly sticky bolt lift and a very slight ejector mark; very slight mark. Anyway shots number 2-6 made a group of 2 1/8". I will load 79 grains with different primers and see what happens. By the way 79 grains was barely compress. Velocities started at 2,839 and went to 2,946. The load, 79 grains, recorded 2,903 feet per second.
If someone knows how to post a photo from a text, and will help, I can text it them. For some reason the computer is not recognizing photos from the new phone.