Since I can't get my hands on the real thing, I've seriously considered doing something similar with paintball markers (guns). There is a company called specail ops paintball that sells a kit to add to two Tippmann A5 paintball markers. It has a bracket to mount them side by side and add a rotary crank to move both triggers. It says it can fire 30 paintballs/second. Now I have an A5 and know it can probably easily do at least 10/sec, so I would bet at least 20 is reasonable. The A5's normal hopper holds about 200 paintballs, so you should be able to empty both of them in about 20 seconds of firing at top speed. I know it's not the real thing, but I could have fun with that next time we go "play in the woods"!