I've Decided building a ball valve air gun

[omar123omar]

Don't worry guys, I have all the parts but have some questions!!!

This is the ball valve with its extensions
http://www.flickr.com/photos/bulletman/4042762697/

This is the pressure chamber i'll be using.

http://www.flickr.com/photos/bulletman/4042762705/

for this pressure chamber, how many psi will it be for its max?
And If I use a standard pipe, drill a hole in a end cap, put some o-rings and finally add a tire valve and screw it in the elbow will it be better?

This barrel i'll be using:

http://www.flickr.com/photos/bulletman/4042762725/

barrel attached to the ball valve

http://www.flickr.com/photos/bulletman/4042762721/

for the barrel is it good or If i use a standard pipe it will be better?



and finally, i'll be using plastic airsoft bb's for the projectile.

Should I put a kleenex tissue inside barrel, put the bb's inside and fire or making a piston valve is better?[/img]