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Barrel sealing Marble Sawed-Off to Sniper

Posted: Wed Mar 28, 2007 12:02 am
by Mitchza89
Hey guys,

This is my 3rd Pneumatic. Its a Barrel-Sealing Piston gun made from Poly Pipe and fittings with a coke bottle chamber. It goes from a very powerful Sawn-off to very very powerful Sniper with screwed on barrel extention. In sniper mode, at 110psi I can get roughly 703fps but I intend to make a Poly chamber and crack it to 160psi which gives me 802fps.

Thanks alot,

Mitch

Posted: Wed Mar 28, 2007 12:05 am
by MrCrowley
Not bad...I like the sawn off style :twisted:

Re: Barrel sealing Marble Sawed-Off to Sniper

Posted: Wed Mar 28, 2007 1:15 am
by TwitchTheAussie
Mitchza89 wrote:Hey guys,

I intend to make a Poly chamber and crack it to 160psi which gives me 802fps.

Thanks alot,

Mitch
I wouldnt go near that number without something covering the bottle. Lacerations arent really nice just ask me and some others who took thngs a bit further.

Anyways I like it. It has the looks and the power. Nice work :P

Posted: Wed Mar 28, 2007 1:40 am
by Mitchza89
Haha ya might wanna read that part again "I intend to make a Poly chamber" :P that stuff can be taken up to 500psi. There is no way Id ever go to that sorta pressure with a bottle. Thanks alot for the comment :D

Posted: Wed Mar 28, 2007 2:01 am
by Pete Zaria
Very nice design.

What size porting is your piston? May I ask what you used for a piston material? I see it's vented by a 1" modified sprinkler, that must actuate the piston VERY quickly.

My only complaint is the schrader in the pop bottle, that would weaken it a bit I'd think...

I can't wait to see the polymer chamber, I hope it has much more volume than a coke bottle... a valve that nice deserves it :) Keep in mind not to go over the sprinkler valve's rated pressure, or switch to a higher-rated pilot valve when you get the poly chamber.

Peace,
Pete Zaria.

Posted: Wed Mar 28, 2007 2:21 am
by Mitchza89
Thanks alot for that Pete.

Yeah the bottle and the Sprinker Valve were from my old gun, hence why the Schrader is in the bottle. I'm going to get a brand new bottle and keep it completely intact concidering I fill it up from the Schrader next the Sprinker Valve so the new bottle should be alot stronger.

The piston is made from a rubber cork that fits perfectly inside the T. I have a soft Neoprene washer thats screwed onto it. I originally glued it on but when the piston opened, the 110psi just ripped it straight off and blew it out the barrel, but with the screw, it stays on perfectly :D

When I eventually do make the Poly chamber and crank it up to 160 or more psi, I'll remove the Sprinkler valve and just stick on a Modded Blow Gun. But I doubt I'd need to crank it much higher then 150psi really...the power I have now is more then enough to keep me satisfied for now :D

All the best mate,

Mitch

Posted: Wed Mar 28, 2007 2:35 am
by experament-u2
it looks sick and would look even better with a poly chamber and if u could give the valve a coat of paint that would look mad to

i wish i could get my piston gun working
oh and a quick question do u have a spring pushing ur piston forwards?

Posted: Wed Mar 28, 2007 2:53 am
by TwitchTheAussie
Mitchza89 wrote:Haha ya might wanna read that part again "I intend to make a Poly chamber" :P that stuff can be taken up to 500psi. There is no way Id ever go to that sorta pressure with a bottle. Thanks alot for the comment :D
Sorry thats my bad I have the habit of mis-reading occasionally :lol: Cant wait to se the poly chamber :P

Posted: Wed Mar 28, 2007 2:57 am
by Mitchza89
Nah it doesn't have a spring. It just seals up against the barrel in the very first pump of my bike pump. How come your piston gun isn't working? It took me so long to get the piston working well. Probably about a full day of tinkering in the shed :?

Lol not a problem TwitchTheAussie....I do it all the time :P

Posted: Wed Mar 28, 2007 3:05 am
by killagorrila99
Is that sprinkler valve metal???

Posted: Wed Mar 28, 2007 3:07 am
by Mitchza89
Nah it's only plastic. I'm not that rich :P

Posted: Wed Mar 28, 2007 3:08 am
by killagorrila99
So it's plastic, yet rated to 150 psi?
Can I have it? I'll send ya lots of money :wink:

Posted: Wed Mar 28, 2007 3:14 am
by Mitchza89
Lol all the sprinkler valves I've seen are rated to 150psi. With the one ya see on this one, I got it off eBay for 20 bucks brand new.

Posted: Thu Mar 29, 2007 6:58 am
by rna_duelers
Nice cannon and there is nothing wrong with soda bottle chambers,they dont hurt when they explode anyways well not as bad as thought it would be.

Man 700fps+ is damn nice.What weight projectile but?

Posted: Thu Mar 29, 2007 7:01 am
by Mitchza89
Just a marble. I'm not too sure about the weight but it's either 4 or 10 grams haha.

Thanks for the comment.

Mitch.