Buck75,
HiMtnHntr has is right in every aspect! but, know that Nosler brass has historically been heavier than other brands which tends to reduce your max load by a few grains.
It may not be your situation but, I will share what I experienced with 7 STW which uses the 8RM as a parent case. I was having trouble finding Nosler brass and ended up buying 50 federal and 50 Remington to try.
I load 7 STW (and others) with Nosler brass, exclusively, for their quality and consistent weight/volume. Nosler was definitely heavier (held less volume) yet, dramatically more consistent than federal and especially Remington brass when I compared a few years back.
Looking at my notes, Extreme accuracy with the 180 Berger/Nosler brass, running 77.5 grains of H1000 max load @ 3040 fps with es of 9. I can get 5 and sometimes 8 firings with these Nosler cases. On the other hand, Federal Brass with the same components, I can ran up to 80.5 grains (3160fps) chasing an accuracy node before I get consistent max pressure signs. The velocity was substantially better but, ES was terrible all the way up, too many fliers and I could only get two firings from federal cases before primer pockets got loose or neck split. Hope this helps...
I would expect to see what you are seeing if all else is equal.
Regards,
100%