Pneumatic Pen-gun Project

[Proxywars]

I wanted to make a pengun for a long time now and my first project didn't work well. My air compressor goes up to 150psi. The space between my barrel and body was 1/16". Air leaked constantly out the barrel. I need a gun that will 100% work. I understand the concepts. If someone can spoon feed me exactly what I need and how to do it. I will be very much appreciated. The gun im thinking about is something such.

[MrCrowley]

Only 150PSI? Forget about it. Buy a shock pump that can do at least 300PSI or build a bigger gun. Something this small at such a low pressure is not very fun.

[Proxywars]

Mmk ill get a 400PSI shock pump today. Hopefully find a mouse pad. Any sugestions with pipe sizes? I also dont know how much space between the barrel and valve with the mouse pad piston between.

[Gun Freak]

Use a rubber stopper piston, it's like 50 cents and one piece.

[Proxywars]

Theres no science stores by my house. I'm a complete noob where can I buy it in stores?

[Gun Freak]

Hardware stores. I saw them in ace today.

[Proxywars]

Wat isle lol in 9th grade and idk how to spell it

[Gun Freak]

The isle with the nuts and bolts.

[Proxywars]

I'll do that wat pipes should i get?

[Gun Freak]

1/8" barrel is good and ~8mm ID chamber is fine.

[Proxywars]

Okay cool I'll look for a plumbing store

[Gun Freak]

You can probably find the pipe at the same store as the rubber stopper.

[Proxywars]

Lowes has pipes to a min of 1/4" =/

[Gun Freak]

I was talking about the hardware store. They normally carry (in the USA)K & S Engineering tubing, which is what a lot of people here use. I use it, it's really good stuff.

[Proxywars]

IK they only carry brass pipes at a min of 1/4" and alot of small fittings and pvc =/