I assume that you are asking about a PCP class rifle. It will kill just about anything you can hit. But I would stay away from Elephants and Bears. A head shot is preferred.
No. The Browning .50 caliber machinegun, sometimes called the "Ma Duece" (for M2) is a belt fed machinegun. It weighs 78 pounds, not something you want to carry around.
It has been reported that the muzzle blast "sound" of a .50 BMG is at or above 180 decibels at a distances up to around 5 feet. That is enough overpressure to cause permanent hearing loss. Note:...