@PotatoEnemy, yes, it's homemade.
@Fnord, the owner of the plate says it's painted copper.
On poor man's chronometer (aka coke bottle) I get 400-450 fps so it's an airsoft rifle. Crap, time to find me a compressor

Some updates: - I found the plate I mentioned in the first post. Bad news, it's not aluminum, it's some kind of soft metal :( - I'm now going to try for a different design, along the lines of a Girandoni air rifle. First tests show a decrease in power comparing to the piston valve, not too happy abo...

Awesome!
Single shot I suppose. What's the pressure you fire at?

Sorry for the delay, I was a little busy.

@Fexo, the barrel is floating inside the the outer tube. I have no leaks in the breach when firing.

@Wyz, I only get 3-5 shots from one fill at almost the same power as green gas.

I modified the container a long time ago in order to refill my airsoft pistol with compressed air instead of green gas. And the ball valve was epoxied in place.

That's not the plate I was talking about, that's an aluminum can I shot today. I'll have to get back to the city and look for the 'original' plate to make sure. As for today's can: wall thickness is about 0.5 mm and bottom thickness about 1 mm. Hmm, strange, did another shot, from 7 m this time at t...

It bulged the plate, about 2 mm.
OK, some pictures in the first post.

It didn't penetrate. I said almost penetrated.

I hope to upload some pics and maybe a video this weekend so stay tuned.

I have a 7 yo daughter, where do you think I got the name from?

The blowgun is from Praktier, a local DIY store. It's a cheap model, rated for 10 bar max.

Oops, my mistake for not being clear.
I drilled the gas container, screwed the ball valve and the schrader valve and used a lot of epoxy to make sure there are no leaks.
As for the aluminium foil, you have to excuse me, English is not my native language, I mean solid aluminium plate.

My first ever pneumatic rifle! Materials: - BB rifle barrel, 6,03 mm ID encased in a 1 cm brass tube - green gas container - schrader valve - piston valve inside a 1/2 T - ball valve - blowgun - wood :D It's still a work in progress as I only have time during the weekends. http://alec.home.ro/IMG_00...