personal grenade launcher

[Hubb]

I had a problem with my breech loading system like this for paintball opening up on me when I fired it. To fix it, I did this. It may or may not be of interest to you.

The only other concern I see is the fact that there is no expansion chamber for the CO2, which has already been pointed out above.

Anyway, I like the design and nice shoes .

[quiggly17]

thanks for the help i actually like that design and im thinking of stealing it

but can anyone help me with the expansion chamber i want it to be about 100 tom 125 psi and i was thinking metal 1in pipe would about 6in of pipe do the job

[Eddbot]

nice gun, my friend really wants an M203 that costs like a hundred bucks, and i keep tellin him it'd be cheaper to make one, now i got proof

edit: does benstern just wander around the site looking for minor infractions of the rules? cause every post of his that i've read is a quote from the rules if were not allowed to talk about "incendiary devices" why would they put this in the smilies :bom:

[Hubb]

thanks for the help i actually like that design and im thinking of stealing it

but can anyone help me with the expansion chamber i want it to be about 100 tom 125 psi and i was thinking metal 1in pipe would about 6in of pipe do the job

Well, you can't....just kidding, that's why I posted it

As far as trying to obtain 100 to 125 psi from a 12g, I used my CO2 Calculator and came up with about 33 to 45 cu. in. needed. Your pipe would be around 4.5 to 5 cu. in. so no. That sized pipe would be pressurized to the max output pressure of the 12g.

If I were you, I would input the numbers into GGDT and figure out what velocity you want to shoot at (should be around 250fps if you're using rockets in paintball). Then, from there, I could assist in finding the right sized pipe for the right sized pressures.

Edit: I just noticed something about your design. It appears that you are going for the M-203 look. If so, you are going to want to keep the chamber small (for the looks). To compensate for the smaller chamber, the pressure is going to have to be raised. This means that your chamber is likely to have higher pressures than what your valve is rated for. Drop the valve and grab you a brass ball valve (which will also cut down on bulk).

You could always opt for a coaxial, but that would eliminate the breech loading process.

Looking over the aesthetics of your design, I know that part of building a paintball launcher is having it look good for the game (make it intimidating). I would also suggest loosing the hose clamps and gluing the PVC together (followed by a paint job).

[quiggly17]

i wonder if a put a ball valve on the gun could i get away with using just the co2 adapter hooked straight to it with no expansion chamber just a thought

[grumpy]

no that would not work the way you are thinking, there would not be enough pressure build up. it may launch but i don't think you would get much distance.

i don't know why i didn't think of this already, you don't need a pressure chamber just use a burst disk. iknow of a player that built a launcher very much like yours using a burst disk without any pressure chamber, he was using it in a game i played at camp blanding and was very effective with it, somewhere on my pc i have the plans for it i'll see if i can find them and post them for you.

[quiggly17]

thanks that would be great bcausei wanted to add just 1in pipefor a chamber and not go any bigger but i would have to add three feet so i figured i would have to make it into a stock but i dont want to

[quiggly17]

ive looked at alot of burst disc guns but that makes the whole breach loader useless because the only reason its there is for a quik reload and fire with a burst disc i have one shot im putting a ball valve on it and makeing the expansion chamber a stock i will see how it goes pics and vids will be up soon after the holidays merry x-mas

[BigGrib]

looks ok to me, needs to be cleaned up a bit, nice 3/3 on the feet,