Depends what kind of pellet rifle. In springers they say it will ruin your spring due to the light weight. People also say the bb jumps around in the barrel messing up the rifling. In a pnematic, most of the time the diameter is smaller than a pellet with the steel bb so you get the bouncing around in the barrel. There are lead bb, which would be better, but you still have the low mass for a springer which causes the spring to slam forward harder. I do shoot bb in a cheap pnematic from time to time to dissuade mean chicken with 1 or 2 pumps as not to break the skin. The bb flies to the right about 2 foot at 60-70 yards. These are just the cheap copper coated bb.
