Interesting result with my .243
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...