Pointing a loadedweapon at anybody is grounds for a felony charge of assault, and brandishing a gun in front of a police officer is an affront to law enforcement that is seldom taken lightly.
Individual states did recognize a right to travel armed with a musket to meet the legal obligation to attend militia musters, but states and localities regulated the exercise of this right and in some cases prohibited traveling with a loadedweapon or discharging a weapon at or near a muster.
Each weapon automatically replenishes its ammunition, but because of the long ammo-reload times, you have to cycle constantly through the weapon list to keep a loaded gun up.