For some reason I’ve been playing around with our LEGO Technics quite a bit lately and built a bunch of different rubberband guns over the past few days. The one above was a good attempt, but them I started getting a little crazy with gear reduction.
This one has a firing ratio of 4/3 (20 positions on loading gear, 15 trigger pulls for 1 complete revolution)
This gun has a firing ratio of 8/9 (8 positions on the loading gear, 9 trigger pulls for 1 revolution)
Finally, this one has a firing ratio of 1/1, though it took an excessive amount of gearing to get there.