When I was a kid, my grandfather set up a shooting range in his basement for us kids. Behind targets was heavy rubber sheet curved back slightly towards the shooter at the bottom.  Below that he made a trough that caught 95% of the BB's. The rest jumped out of the pan and ran around the concrete floor until we figured out to put a piece of shag carpet under the trough.  This caught the rest of the BB's and we use a magnet to collect them out of the rug.  Later he made a motorized moving target like in the fair shooting arcades with ducks cut out of a small rubber tire and attached to hinges on a rubber belt turned by slow electric motor.  Good times. He was an excellent shot and I've seen him shoot barn swallows out of the air with a .22.  Could also toss coins into the air with his left hand and hit with BB's shot with his right hand.  He carried .22 rifle with him everywhere. Once, it fell off his tractor while shredding and bent the barrel. He managed to straighten it back out like new.