If it's within the regs, I'd get a 45-70 and load it any which way you like. Personally, I've gotten partial to the Hornady 250gr MonoFlex (all copper) bullets for whitetails. Far less recoil than the heavies and very lethal on whitetails. My Marlin shoots them well at 200yds but I consider the rifle a 100-150yd gun anyway.