Figured I'd finally follow up on what I did with the sch 10 stainless pipe I bought last year. This is it. The design really isn't that optimum for performance. In fact, it's not particularly impressive. But the gun shoulders nicely and is easy to aim given the limited accurate range of golf balls (SLICE!).
In any event....
Barrel: 6' of 1.5" sch 10 stainless steel sleaved inside 6" of 2" sch 80 to provide an easy way to connect it to the valve.
Valve: 1.5" Asco pulse valve.
Pressure: I've had it to 150 psi. No real intention of going higher.
Velocity: 600 fps (measured with commercial chrony).

Here we have a close up of the trigger/safety assembly. 'Tis the only part of the gun that is (IMO) clever in any way. As you can see I fed the vent through the chamber. This makes for a clean mounting for the trigger.

And here is a sequence of pics to show the loading sequence. It goes pretty quick and easy.
