What will a pellet gun do to a raccoon?

It depends on the size of the raccoon, the pellet and the power of the rifle. If you intend to kill the raccoon, then I would suggest hunting pellets ( called hollow point pellets ) and using a .22 caliber pellet rifle. Do not use a BB gun. Hollow point pellets deform when they hit a target and have maximum knockdown power. A head shot is the most humane shot.