Re: 7 saum and h50bmg??
You'll never get enough powder in the case for any performance. Back down to H1000, IMR 7828, N570 range.
You should list where you're located, a lot of people will help out locally. RL 25 is another good powder for 180 class bullets, and was just available yesterday. I'm on my 5th saum, and I don't agree with the guys running H4350, and 4831, too fast in my opinion.