LOL! One of my fellow range instructors once told a young Marine to "get his face tight against" the butt of the Mossberg pump hew was fam firing, and when the whistle blew, the lad brought the butt up against his chin instead of his shoulder.
Ouch!
Range sergeant my husband knew used to show off by firing the M-14 off his chin and less mentionable places . . . it CAN be done . . . (so says my husband.) < g >