Yes, metal is even better because it is less affected by CO2 temperature, unlike pvc. Go for it!

I remember seeing a metal pipe on Mcmaster that had really good dimensions for a paintball barrel, for a good price, but I lost the link.

Good luck!

Low flow 3-way, then? Is it one of those custom made, push button ones mentioned in an earlier thread? Do you have a link?

.69-.71 Depending on your paint-to-bore match.
Generally, the closer to .69, the better, as you need a tight fit with room for paintball moisture expansion. I used sch 120 pvc. works great.

Uhh, I don't see how that is semi auto w/o another valve?

A qev piloted by another qev? I know the part you plan to use, but isnt it a little overkill?

Dang, I look forward to seeing your nifty new trigger setup... cause I'm using a similar design...

Wow, Awesome idea. Since my paintball gun is having problems, I may need to use your idea.

How easy/hard is it to pull the trigger? (How many times can you trigger per second?)

Also, I could not find the three-way you are using? Was it custom, or do you have a link?

Yeah, I think I will. Dang, gotta get to home depot.

No, it has better performance than a sprinkler, but less than a piston. QEVs are awesome because of their fast opening time. The difference is that it closes immediately after firing. It is fired by cutting off input of air and releasing the air from that area. http://nerfhaven.com/homemade/zero_sem...

A QEV , or Quick Exhaust Valve, is basically a 3-way variation on the piston valve. http://www.spudfiles.com/spud_wiki/images/6/65/Qev.gif When air comes from the source (1) , it closes the barrel (3) and goes to the chamber (2). When the pilot is vented, the piston opens the path from the chamber t...

Hmm, some very useful info here. Nice to see an idea backed up by a working model! I do think it is an original idea; wish you luck.

The semi-auto design on nerf haven would be good to fill/pilot a QEV. It seems like a variation of a sleeve valve or spool valve.

Wow, behold the future of pneumatics. BTB, you giving out autographs?

Seriously, the drawing and explanation were easy to understand, and it does not look that hard to make with the right tools. Awesome worthy.

Wow, that is awesome! It looks like its from.... I don't know what, but it looks amazing!

Well, I've got together most of the materials, and have begun assembly. So far, I turned the barrel down to sleeve into 1" sch 40 pvc, modded the ammo feed tee, cut some pipe and dry fitted stuff together. The paintballs have an excellent fit into the 3/4" sch 120 pvc. Using the barrel like a blowgu...

Thanks, I remember seeing that article, but I lost it. Thanks for the link.

Also, I am kinda locked into using a 3/4" QEV; I already have it. Not too many ways to get rid of the pilot, or pilot volume, without limiting flow.