Yes, it
would be too big.
Idaho, for example, has a 16 lb weight limit for rifles*. The limit was put in place, to specifically prevent .50 BMG and larger weapons from being used to hunt big game. The cartridges have not been banned, but you have to be tough enough to use them in a shoulder-fired weapon, that weighs no more than 16 lbs. (Even if you think you're tough enough... Your doctor will disagree, when your torn retina and bloody nose take you to his office.) A niche rifle was designed to combat this limitation: The
Desert Rhino. Few were made. Most remain unfired.
*I believe the limit is for all weapons, but don't recall for certain. If it specified only "rifles", we'd certainly see people building 180 lb "pistols" in .50 BMG. (Technically an "Any Other Weapon", since it would not be designed to be fired with a single hand, would not be designed to be shoulder fired, and would not be a shotgun.)