It sounds like you are making a recoil shock. I think it would work well if you can find the right spring.

With the 3/4 valve it doesn't have any noticed recoil but you could make a track for your cannon to sit on and put bearings under it with a return spring with the right spring I think that would be a good recoil system.

The tractor is not mine it is a neighbors he uses it around his farm we are working on it. the truck is just an old ford i use around the farm it still runs good but i have not had it on the highway in a few years. and the 3/4 sprinkler valve is small but it was the only one i could find at the loca...

Thanks I will try and post a video sometime around the weekend

simple breach loading air howitzer :D it is made out of a bicycle, treadmill, satellite dish components, a sprinkler valve, and some PVC pipe. It was mostly junk i had laying around the shop.The air tank is made out of a satellite dish post i cut it to length and welded ends on it. i put a metal val...