I know a guy that mounted two Ruger 10/22s to a dirt bike's handlebars and then fabricated a hand crank system so they could be rapid fired by turning the crank with the left hand, as you controlled your speed and turning with the right.
It was fun, and beer was most certintly involved.
Neighbor did two SKS's on a tripod, each crank fired 4 rounds, was kinda fun
