SpudFiles

Well besides Spuddin and such i have another cool hobby(one of several)
I like to restore and drive Military Vehicles and one of my favorite vehicles is my m274 Anti Tank vehicle . My problem is a Real 106mm recoilless Rifle costs lots but a pvc one wont cost much .It has to be pneumatic and it has to look real . I need ideas and such i have a few but many heads are better than mine.

That tank looks sweet but you shouldn't use that sized barrel if you are replicating it maybe you should use a 2'' barrel 8' long. By my limited spud exsperience That barrel would require huge uses of air. as in a chammber maybe the same size as the barrel maybe you should make a co-axial with a barrel shorter than the barrel I suggested.

So it has to shoot? Whatever you build that big is gonna be LOUD and its going to have a lot of recoil.

The cool thing about spud guns is that they truly are limited to your imagination. looking at the rear of the gun it looks like you would have to make that out of something like fiber glass or maybe even wood if you have the tools. im assuming that you have metal working tools because you restore verhicles, so you could also make the rear part out of sheet metal.

pvc, as you said, is cheap, but at the length given in the picture, it isnt very ridged and will probably bend very easily and maybe even break if you go on rough terrain. my recommendation is, again, to find some fiberglass pipe. i dont know where to get it, but i know that they use it for steam applications.

another idea is to have two barrels. one functional, one not. the outer barrel will be for appearance and have a inner barrel for functionality. if i were you i would make the inner barrel just slightly smaller than the outer barrel. iron or steel pipe would probably be best. check junk yards and scrap metal places because steel pipe isnt cheap.

as for a valve your best be it probably a burst disk because is is powerful and is also inline, which will help appearance.

keep us updated, that will be a nice gun when finished.

edit- coaxial would also work and is probably a good idea, but i dont think you can mount it exactly as pictured.

pizlo wrote:So it has to shoot? Whatever you build that big is gonna be LOUD and its going to have a lot of recoil.

not compared to the real thing...

Didn't he say the gun mount didn't have recoil hence recoiless?

The 106mm recoilless rifle has a profile which lends itself nicely to spudgun construction, you can hide a lot of things in that thickness of pipe. What sort of power were you looking to obtain?

My original plan was for a 106mm barrel(Softball) but the pressure needed for such a thing...... So i am settling for a Golfball barrel , i built a golfball/tennis gun (need to post) i like da distance
Here is a little draw"in of what I was thinkin of
Please tell me flaws you see I am all ears

Here

Scrap the sprinkler valve, and make it a light weight piston with small volume

That will get you the power you want.

"light weight piston with small volume" ?
I have little knowledge.-Statement
I dont know how i would incorporate that into my design can you give me a little more of a idea,Pics are worth a couple of words
Thanks for all the help so far

Ok this should explain it all, just add in what size barrel, chamber and fittings and there you go.

Nowt wrong with your original design either if you can find a big enough sprinkler valve, bigger = better performance, but in terms of sheer power a piston design well made will give you the edge.