SpudFiles

Ok , so i've seen alot of posts of people showing their designs for a piston...very awesome. i know how they work, but cant seem to find anything on how to make the guns. I want to make a coaxial gun. I can imagine how you attach barrel inside chamber, reducer at end, but what holds the barrel in center of chamber where the piston meets it ? or does it just hang freely inside?

You need to make a homemade supporter fro an adapter. If you want plans, use google.

or use spudwiki

I didn't use a barrel suporter as I used copper to make my piston gun.

I just played around with the copper until it was centraly in the 22mm pipe.

i did a google on coaxial..all i see are finished products..anyone have a few pics of how its pic together and whats used ?

Check the pneumatic showcase section, there are lots of coaxial examples. Here's a video that shows how to make a piston valve for an over-under cannon, it's the same concept as a piston valve for a coaxial.

http://www.bcvids.com/dload.php?action=file&file_id=4