An initial attempt at making a remotely powerful rubber band gun...
this rifle can hold 3 sizes of rubber band, with up to 4 rounds!
About this creation
A close-up look at the rotating firing bar.
When the trigger is pulled, it allows the bar to rotate clockwise to start the release of the round.
Then when the trigger is released this allows the bar to rotate further.....
.....allowing it to do a full rotation and release the rubber band, whilst also resetting itself for the next shot (semi-automatic mechanism).
This trigger system works very well for this type of gun, since semi-automatic rifles in real life generally don't have many shots in a magazine.
Of course due to its construction it's not so good for holding many rounds, because the trigger need not move far to create a mis-fire which would release all the rounds at once (due to the high torque being created by so many rubber bands).
The file below is the full gun, but feel free just to use the mechanism!