In Michigan it is legal: direct quote from the game regs:
"In the rifle zone, deer may be taken with handguns, rifles, bows and arrows, shotguns and muzzleloading firearms including black powder handguns. It is legal to hunt deer in the rifle zone with any caliber of firearm except a .22 caliber or smaller rimfire (rifle or handgun)."
That said, I would use my 50 or 54 if deer hunting.