Mag for rubber band gun rev.03

This is inspired by this: http://www.thingiverse.com/thing:268524
I printed this gun for the kids: http://www.thingiverse.com/thing:518796
And then I thought the mag was looking pretty cool, I printed it without checking into any details. That mag does not fit this gun, it is for an older version of the same gun. So I designed my own mag to fit this rev.3 gun.

There is a boss on the mag, with the same shape as the pocket on the gun, it fits in there very nicely. So before tightening all