She is shooting a 12 gauge. The shells have been loaded very light (but can be loaded even lighter). Having a big, heavy gun also helps with the recoil. Buckaroos and buckarettes still have to hit all their targets. Because they may be shooting .22s and other light loads, knockdowns will not always go down so that is not required. With the shotgun, if one bb hits the target, they are good (benefit of the doubt goes to the shooter).