I've tried h4831, rl22, retumbo, imr7828, and h-1000 in 7mag with 160 accubonds. I shot a few 140s with rl22 and retumbo.
Rl22 was accurate with both bullets but shot different velocities at different temperatures. I won't buy any more RL powders.
Retumbo got the 160 to over 3000 fps but not great accuracy.
H4831 worked well but I had to load it way over hodgdons max load to get any decent velocity.
I like h1000 with 168 bergers. It will get the bergers around 3050 in my 24" barrel, but I load it at 2900 for best accuracy. With retumbo and h1000 I can stay close to book max and get decent velocity.
My 7mag will have a new barrel on it in a few weeks so I'll have to start my load development again. I will start with h-1000 first, then retumbo if I need to.
My 7mag loads really began to shine when I switched from a Federal mag primer to a winchester large rifle primer. I lost a little velocity but my group size and ES/SD shrank. I can get the velocity back with a little more powder.
Good luck to you and I hope this helps.