my first piston valve

[sniper hero]

I made today a piston valve I planned to make quite a while.
I had to deconstruct one of my guns but it's no problem for me

specs:
the piston is made of hot glue and a rubber ring.
all in a 3/4 T-piece
the piston slides in a 3/4 nipple
the opperating pressure is around 11bars (sometimes 14 sometimes 8)
it's filled by a regular bike tire valve(opens easily so I need some good pumps before the piston seals
the chamber is made from 350mm of 28mm copper pipe with an endcap soldered on.


I did some test shots:D
pics of one shot through 3 metal plates(thin), it left a big mark on the wooden back stop.
the ammo was just a fast put together thong made of a quickdisconnect fitting a piece of plastic pipe and some tape to fill up the hole.

please comment and ask your questions

[Brian the brain]

Great damage!!
Looking good so far

[jrrdw]

More details please. Maybe a video???

[sniper hero]

More details please. Maybe a video???

what would you like to know more ?

I will post a vid as soon as possible

[jrrdw]

Operating pressure, parts measurments, is that a steel plate your cutting ammo from? The details.

[sniper hero]

I added some specs in the first post
I plan some improvements and will show as soon as I finished them.
because of some problems uploading a video I'll put it on video google and put a link here.

EDIT: [GVideo]http://video.google.com/videoplay?docid ... 5344293063[/GVideo]
haha you can hear my dad it actually sounds fairly quiet but it is very loud inside my room without the barrel attached.

Edit by jrrdw

[psycix]

Very nice!
Good job on that piston.
Does it slide in a pipe or just in the T?

EDIT:
Ah you just edited the answer into your post!

[ramses]

nice gun! you would definitely get better performance if you enlarged the porting on the piston valve.

can I ask how you got whatever you used for the sealing pipe into the back of the bushing? dremel?