Where can I find load Data for 45-70 loads with hard cast 420gr 450gr etc.? Thank you for your help.

MD, if you don't want to play around, try some of the loads from Garrett and Buffalo Bore. They'll get your attention!

Mad,
One thing you need to know first is the strength of your action !

Hip

I have a marlin guide gun. And I’ve tried Garrett there very hot. I just like to reload.

Western Powder manual has some loads sir.
http://www.accuratepowder.com/...uide1-2016_Web-1.pdf

Try http//.www.beartoothbullets.com they usually have data.

Hip

maddog--Try 40 grains of 3031 with the 420 or 450 grain cast bullet. Nowhere near a maximum load, but will give you plenty of horsepower to do anything you need with a flatnosed hardcast bullet, even on the big bears.

I have a friend that shot a grizzly that squared just under nine feet with a Lyman 457121 480 grain flatnosed bullet square in the chest at 60 yards. The bullet exited the bear's left rear ham. He had loaded it with 38.5 grains of 3031 and used his 86 Winchester. One shot, down and done. The bullet was cast from 50/50 wheel weights and lead. I am certain of this, as I cast the bullets myself and sent them to him.

Thanks guys for all the help!!
Much Appreciated.