Notice its on skids...you just drag it or tow behind your hunting rig. The perfect road hunting gun. I think its a 20MM. The guy that built my .50 said he built a 20mm....shot it one time and that was enough.
Eel, if you attach that thing to your scull boat, you've got a punt gun. Too tired to scull back to the ramp, just point the stern in the direction you want to go and pull the trigger, that'll send you all the way back to the ramp.