<img src="http://i39.tinypic.com/2whijis.jpg">
The gun is a modified copy of a design that I found, called the <a href="http://win.xrea.jp/p212.html">P212 PULL AU*TO</a> , from OGG CRAFT'S GUN LOCKER.
The gun body was carved from a single piece of 3/4" x 5-1/2" pine board, using a table saw and jig saw. - The notches for the rubber bands were cut on the table saw. Had to take the blade guard off (NOT RECOMMENDED) and now I'm covered in sawdust.

The "ramp" on the pull handle is apparently too high and too deep, as the rubber bands will bind if you load every notch. There are 20 notches total, although I'm only using every other one.
The OGG CRAFT site has some really cool designs on it. I just though that this one looked like the most simple to replicate. (My woodworking skills are below retarded).
<a href="http://i43.tinypic.com/mmfrj8.jpg"><img src="http://i43.tinypic.com/mmfrj8_th.jpg"></a> <a href="http://i41.tinypic.com/v4bct0.jpg"><img src="http://i41.tinypic.com/v4bct0_th.jpg"></a> <a href="http://i41.tinypic.com/2rw016w.jpg"><img src="http://i41.tinypic.com/2rw016w_th.jpg"></a> <a href="http://i44.tinypic.com/ofc87c.jpg"><img src="http://i44.tinypic.com/ofc87c_th.jpg"></a> <a href="http://i41.tinypic.com/30k6req.jpg"><img src="http://i41.tinypic.com/30k6req_th.jpg"></a> <a href="http://i40.tinypic.com/30u8j28.jpg"><img src="http://i40.tinypic.com/30u8j28_th.jpg"></a>