Lee cast bullet in the 7Mag with 2 grains of Bullseye with a cotton wad over the top. Great part was, I could retrieve the bullets out of the tub and recycle them in the lead pot!
Fast forward...if I can shoot a 7Mag in the basement, surely I can kill a squirrel (and a duck, too) with round balls in the .458.
Oh yeah.
Don't try this at home...