I loaded some cast performance 460gr gc bullets with RL-7
37gr,38gr,39gr for my 45-70 marlin guide gun.38gr averaged
1500fps thru my F-1.I'm going to try IMR-4198 next.

Do you think a slower powder than RL-7 or the 4198s may be better for the heavier bullets in the .45-70? I have some hard cast 420 gr.'ers coming and I'm thinking maybe (hopefully, because I have lots!) that Varget might be OK?

I like IMR-4198 powder for the 420gr WLNGC CP bullets.I got super groups with 38,39gr of IMR-4198.CCI-200 W-W cases.I still will try the 460 cp with IMR-4198 and see what shoots best.These 460gr cp bullets really thump the shoulder.try that 38,39gr load for the 420gr bullets.