IMR 4350 has always been my go to powder for my 7mm and .300 Win. magnums. I took my old 7 mag. out of the gun case a few years ago with the idea of hunting a powerline with it. I also decided to try the Nosler Ballistic tip bullets, since I had tried 140 grain partitions and 139 grain Hornady's before and never got good groupings I decided to try the 150 grain bullets.
With a moderate load of IMR 4350 I was able to get good repeatable groupings but when I stepped up the load the group always opened up. Sticking with IMR 4350 I tried come CBT 150 grain BT plated bullets. These bullets grouped better at the loads nearing max. but not great while retaining good groups at the moderate load. I went with the heaviest loads that still gave me usable accuracy.
Next time I work up loads I will have a better selection of powder to choose from. I just wanted one powder, IMR 4350 to be my all caliber best powder.
To be fair this rifle has never shot lighter bullets well but has done it's best work with 154 and 160 grain bullets. I just wanted to try the lighter ones this time.
I've got old eyes now and all groups were shot with a Leupold 3.5 X 10 on 10 power. With a higher mag. scope or another shooter all these groups probably would have been tighter.