Brass Volume

[270Weatherby]

I have been comparing Weatherby brass vs. nosler brass in 300wby. The Weatherby brass holds atleast 2gr more powder than the nosler brass. I am working loads up with H1000 and 7828ssc. I am finding same powder charge weights are compressed in Nosler brass and not compressed in Wby brass. My question is... how does the case volume affect velocity/pressure? Any advice on this will help.

 

[Mikecr]

It's likely your loads(same loads) in Nosler brass will be higher in pressure/velocity.