Coaxial Paintball Grenade Launcher

[SP00K]

So I have some 2" and 3" scrap pvc laying around. I realized that my paintball grenades fit perfectly inside 2" diameter pipe. So I just came up with a design for a m203 style grenade launcher.

My only question: Is 3" pipe going to be a large enough chamber for a 2" barrel considering it's coaxial? I'm only hoping to get about 100' or so of range. Should I bumb up to a 4" chamber?

This is going to be my first piston coax, so any tips are welcome.

EDIT: pressures of around 100 psi, and the grenades tend to weigh 2 lbs.

[jackssmirkingrevenge]

what pressures are you planning on running at, and how much does the PB grenade weigh?

[Gun Freak]

Plug it in to GGDT and see. Or, do some simple math and determine the CB ratio, that should help a bit if you know the pressure you want to run at (which I presume is around the 100 psi range).

[jackssmirkingrevenge]

With a 3" chamber and 2" barrel, C:B ratio should be around 1:1

[Gun Freak]

Here are the results of a rough model in GGDT, rough because you didn't provide any details of what you planned to build other than barrel chamber and valve.

[Hubb]

Your gonna build a M203 style launcher using 3" pipe? Good luck with that...

[clemsonguy1125]

Make sure your barrel is perfectly centered and the barrel is perfectly flat on the end

[Lockednloaded]

To make an M203 look alike you are going to need a serious redesign. I think you should get a 3/4" QEV and a 3/4" galvanized steel chamber. Run this with your gun's CO2 system unregged through a high pressure slide valve. I have a sketch somewhere, I'll see if i can dig it up if you want

[SP00K]

Awh ballz. I did not mean an m203. I was thinking of a LAW.

Comparing pipe fittings at Home Depot, I decided to bump up to a 4" chamber.

I plan on running at pressures of around 100 psi, and the grenade weighs about 2 pounds (purdy heavy fer spud gun ammo).

I have a 3" end cap that slides up and down perfectly in a 4" chamber which I plan on using for a piston. The only problem is that it has a rounded end. Or is that not a problem? Because I can almost imagine that making a better seal, but I'm not sure what it will do to the piston and air filling actions.

[jackssmirkingrevenge]

Even with a 3" barrel it will have much more muzzle energy than a 9mm pistol bullet at 100 psi, I would not want that sort of projectile flying about while paintballing...

[Hotwired]

the grenade weighs about 2 pounds

Sure you don't want to reconsider this?

That's a serious weight to be firing near people in a game where all other projectiles are very small and light.

2lb grenade vs a visor for example.

[SP00K]

I completely understand your concerns about this. This is more of a for-fun-try-something-new thing.

I do not ever plan on using this in-game. I've had my share of near permanent loss and damage situations and I cannot imagine someone getting hit dead on in the chest (or god forbid, the eye) by accident. I set using this thing in game next to those kids who use combustion cannons in game next to those kids who use firecrackers with airsoft bb's in game.

No, this will never be amongst people.

Plus, nerf vortex footballs will be awesome and I've seen people use homemade rocket launchers in paintball for tanks.