Okay, let’s get some parenting concerns out of the way first: I believe that a rubber band gun is probably one of the safest ways to teach a kid a bit about gun safety, partly because it actually shoots something that can sting. It’s a good excuse to explain that bringing a weapon (even a toy one) to school will likely get him kicked out, and it’s also a good way to learn how to be conscious of where it’s pointing — loaded or not. Plus it’s fun for target practice.
That said, here’s a single-shooter rubber band gun that we threw together today using scrap wood. The rubber band is loaded from the front onto the top of the trigger lever, which is also the rear sight. It’s alarmingly accurate; I can hit a quarter-sized bull’s eye from across the room.
(Click on the pictures to view larger versions.)
It started off as a bamboo flooring plank cut-off, but it wasn’t very accurate or attractive. It was also very difficult to hold and aim.
The blue rubber band provides enough tension to hold the trigger in place when loaded. The trigger lever pivots on a brad nail inside of the groove. It took some chisel work to get the slot just right.