Same bullets, same charges and primers, just different cases.
100 grain Sierra Pro Hunters. 44 and 40 grains of H4831sc in Nosler and Winchester cases, lit with Remington 9 1/2 primers. 2.7 OAL.
With Winchester cases
40 grains 2850 fps
44 grains 3020 fps
With Nosler cases
40 grains 2950 fps
44 grains 3055 fps
I expected more of a difference with the heavier Nosler cases. As a side note. My deer load last year was a 95 grain SST over 44 grains of H4831sc in Winchester brass, Remington 9 1/2 primers OAL 2.635 gave a velocity of 2915 fps.
Curious indeed...