Here is an arrow gun I built up after seeing some yahoo sell one for $1k back East.
I took a Marlin Model 60 and yanked the barrel off and built a new barrel that will allow a sixteen inch arrow to slide over. The gun can push the arrow at ~390 FPS and is very accurate.
The rifle and and arrow
The barrel shroud removed to show the inner barrel the arrow slides onto.
![](http://kc7mrq.home.bresnan.net/pics/HPIM0491.JPG)