Well hbobby your choice of powder is somewhat fast and what you need is a slower powder for the big seven.
Have you read up on the 7mm rem magnum? There's a bunch of stuff written up on loading for it.
I use the 140 grain Accubond, and my powder of choice for that bullet is IMR 4831, 3/4 inches at 100 yds 5 shot group.
Also you might work up your loads by testing at 100 yds (if your zeroed), because it's simple to gather data, and then test out to further ranges.
Good luck with the big seven dude!
