EDIT: Paintballer187 has a great priced tester for sale, with high quality parts. I'd get this one...You can see from the cost fo components that he is doing you a favor! http://www.pbnation.com/showthread.p...5#post26782885
Part #s are from Mcmaster.com
1. Tubing: 5233K51
2. Barb: 5121K35
3. Tester Body: 4429K259
4. Gauge <- any 1/8" NPT will do: 38105K32
5. Bleed valve/plug
Bleed valve: 4886K21 Nptf Male Inlet X Nptf Female Outlet
Install by screwing the barb, plug, and gauge into the body. Loctite if desired. Hook your LPR connection to the barb. Read pressure and adjust to desired. Don't go over 100psi for assembly. If you have the bleed valve installed, purge system before disconnecting hose from barb. You can test the cycling of the gun by installing a second barb ($3 gets you a 10pack) on the end of the bleed valve and hooking into the solenoid, with the valve opened.
While you're shopping mcmaster, do yourself a favor and pick up Oring pick 7388A33.
Disclaimer: Have not tested this. Part #'s all appear to match up. If you turn it up to 120psi and something blows, it's your fault, not mine.
Hope this helps some people.