The tank im using says on it 80 cubic feet!!! Now, 80 cubic feet is 136,000 some odd cubic inches... there is no way that's right. The part where it said 1000ci was on the neck, which has been replaced by a 2'' nipple. I assume that 80 cubic feet, is how much air, when filled to the correct pressure...

looks good. The piston looks very pretty.

Any chance of a video?

MrCrowley wrote: There already is a burst disk hybrid using a similar sized SCUBA tank

The second video in that topic says his tank is 353 cubic inches.
my take is labeled 1000 cubic inches.
It does not look like my tank is 3x the size though...

Either way, a burst disk hybrid should be easy.

Little bit of info on brazing, if done correctly, brazing can be stronger than the metal you are brazing. I did brazing of stainless steel, brass, titanium, and aluminum for about 3 years as a job, every once and a while are parts would be tested in all sorts of fun ways, the SS brazing were able to...

I think we need to get together for a shoot off.. :D 1.9 inch porting T valve and 1,000 cu in vs 2 inch coaxial and 700 cu in. 8) What state are you located in? Im in northern Michigan that is mad what pressure was the vids shots at? About 100 psi in the video. I have taken one shot at 150psi, and ...

I have to laugh (evil laugh) at the idea of a 1000 cubic inch 1.9" porting hybrid... I may do ot in the future... I might be able to get another tank like this one... This one already kicks to much to use the shoulder strap i made. The idea was to fire it from the hip... But it knocks me over at 150...

lol what can I say... I love it of course you do, its piloted by a 3 way valve. (not in the pictures.) :-P Also, i will be getting a new barrel tomorrow, 2''x10' (might cut it down) and shooting 2'' slugs :-) i really have no interest in shooting golf balls, it was just the first thing i had laying...

This is a 2'' porting, (1.9'' actually) metal, piston valve, with a 1000 cubic inch scuba tank as the chamber. Piloted by a 1/4'' QEV. For now, i am using a 2'' barrel, with golf balls... as you can see in the photo below, they are a terrible fit. Soon i will be making some 2'' slugs, and trying sab...

nice video. The death metal was rather... metal-ly.

I would take a good look at using cardboard. might sound hard to work with.... but if this is a one time mold, you should be able to use a combo of cardboard and a good strong tape to make it easily. another option, is foam board, from a craft store, it is about 1/4'' thick and has a VERY slick surf...

800 psi will make the air cylinder punch through any soft ammo. Hard ammo would probably bend the cylinder rod. That is of course.... if the air cylinder body can even withstand the 800 psi, which i doubt. I ran 250 psi into a 1/2'' ID air cylinder... the bolt jammed once, and the cylinder was DESTR...

you pilot valve needs to be faster.
Or, make your piston tighter in the housing.

I would recommend trying a ball valve as a replacement for the blow gun.

Also, the pilot volume seems a little bit massive.

Gun Freak wrote: Cats are the new feet

Lol, i spy a challenge....


back on topic: Looks good, i like the front sight.

get a threaded union.
There will be no need to unscrew the compression fitting.

Also, you could throw a burst disk in the union sometimes, when you need a little extra "oomph"

Braze it.
If done right, it will look the cleanest, and be plenty strong.
I brazed and tig welded SS for 3 years, if you need any help PM me.