Absolutely awesome. Damit i have to build one of these... Phenomenal!
And a quick response to your first answer on adding a second set of teeth for a second shot in one cycle.
I thought about that as well and it would work if you have a second mechanism side by side to the first one.
It could be on top of the first "barrel"
So a fork with two bandsets and two sleds and a slightly bigger wheel on the second mechanism... just like the gears on a bike.
The only issue with that maybe the ammo feeding...
However... absolutely brilliant work.