Forgive me but I'm a bit skeptical. This will propell a tiny bullet to 2700 feet per second from a barrel less than 2 feet long, but that's with 58,000 psi of chamber pressure... Have you tried chronying it with a solid projectile that isn't prone to disintegrating if fired at such a high velocity?

Your chrony's broken

SpudBlaster15 wrote:If you cut large grooves into the PET stock, then applied epoxy, the joint would most likely hold pressure in the same manner a union does, but it certainly wouldn't seal.

If it's holding pressure, then it's sealed. I have tried this before, an peel away like magic it didn't.

"pocket" if you ignore the compressor

j/k, nice work

It doesn't depend on the material in this case but the structure Epoxy does not naturally stick well to PVC, indeed I can make an epoxy piston by filling a section of smooth PVC with epoxy then tapping it out with a hammer. A PET bottle's walls are thin and flimsy, but if there were thick like PVC p...

find some pipe that's the same I/D as the BBs then roll tape around it till it fits the barrel snugly. You could give it a few hammer taps rested on a marble to flare out the breech end to mitigate any alignment issues.

Pressure is just one of the factors affecting BBMG power. You also have to consider valve, chamber size, barrel length and calibre - so pressure alone isn't going to suffice in creating different categories.

Well, there are no threaded sections in my mini-piston design:



It's made purely of epoxy-to-PVC connections and I regularly take it 400 psi and beyond, never had a failure.

COD_FILLETS wrote:Also, I thought caliber was only in inches.

Depends what part of the world you're in, in the US your M16's a 0.223", but in Europe it would be 5.56mm calibre

it's all a matter of preparation - you have to roughen up the surfaces in order to ensure proper adhesion, by doing this I've made epoxy connections that can take in excess of 400 psi without failure.

With consistent ammo (10mm ball bearings) I could hit a 3.5" floppy disk reliably at 20 yards, which is about the best accuracy you can expect from an improvised launcher with a smoothbore barrel.

I would think so, it's a fairly common brand. If you don't find it any 5 minute epoxy will do really, this is just the brand i've got the best results from.

I use this method to attach schraders to all my projects, like this one and this too

First you need to reduce the schrader to bare metal at the base (ie remove the rubber coating along the body), I find that an easy way of doing this is simple scraping off the rubber with a good blade then finish it off with rough sandpaper. You should be left with something like the one illustrated...