In my state, if one is out small game hunting during an open big game season, and carrying a firearm and ammo legal for that big game season, then one had better have the big game license/tag as you will be assumed to be hunting big game. To stay out of trouble, it necessitates using a small game rifle of under .40 caliber (since a .40 is the smallest rifled caliber allowed for deer), a smoothbore under .45 caliber with ball (since a .45 is the smallest smoothbore caliber allowed for deer), or a smoothie of any caliber/gauge while carrying only shot. So sometimes it's not only how one wants to use the gun, but the game laws and/or how they are interpreted, that can be a factor in a decision.