Boynton-Banger shooting red Thera-Band

[BoyntonStu]

Snare knots are your friend.

They allow quick band/tube changes.

The Boynton-Banger has shot an 80 grain (5.2g) marble at 234 fps.

Incidentally, you can reverse the rifle and slide the fork instead of the trigger.

The bands are attached to the fork  by simply wrapping the nylon around the 1/4" bolts.  

The snare knot and the bolt wrap allow for perfect rubber length adjustment.
Snag knots are your friend.

They allow quick band/tube changes.

The Boynton-Banger has shot an 80 grain (5.2g) marble at 234 fps.

Incidentally, you can reverse the rifle and slide the fork instead of the trigger.

The bands are attached to the fork  by simply wrapping the nylon around the 1/4" bolts.  

The snare knot and the bolt wrap allow for perfect rubber length adjustment.

http://www.youtube.com/watch?v=eCHoMt47PjI

[Forum Admin]

I'm very impressed with this design. Does doubling up the bands improve speed much, or does it just allow you to shoot heavier ammo at the same speed? Have you looked into any systems that will mechanically increase the speed of the projectile?

[BoyntonStu]

I'm very impressed with this design. Does doubling up the bands improve speed much, or does it just allow you to shoot heavier ammo at the same speed? Have you looked into any systems that will mechanically increase the speed of the projectile?

All shots with 80 grain glass marble:

Single black TB  - 234 fps  max so far
Single green -  225
Single red – 167
Red + green – 189  Slower than single green.

I have been thinking about a manuballista concept.

Powered arms that draw the rubber as both are fired.