I recently acquired a Tippmann 68 Carbine off of craigslist, and this thing refuses to chrono above 260. When I first got it I pulled it completely apart, replaced all the "o" rings, and dropped a lighter valve spring in the CVX valve. It cycled great, but over the chrono it was maybe shooting 240s. I added the strongest tippmann drive spring I could (red mad man), polished the hammer, and drilled out the cross section in the powertube, backed out the IVG to maximum flow, swapped the screw with a shorter one, and added an RVA (set to all the way in). Also switched to Co2.....this got me to 255 or so. I have confirmed that the linkage arm is straight, it is not bent and glides smoothly. Additionally I have confirmed that the front bolt is fully intact and the hole for the linkage arm in the front bolt is still plugged at the bottom.


At this point what other things can I do to get this thing shooting correctly? Paint was D3fy, shooting out of an .687 8" Lapco Bigshot Barrel. I like to run my guns @ 285 fps and I'm pretty anal about not shooting anything below 275 in an actual game. Ideally I'd like some more home brew mods to get this shooting velocity, but at this point the only other thing I can think of is just picking up a Ninja SHP reg and running 1100 PSI straight into the valve. Are these CVX valves like cockers in the sense that they have a "bell curve" of ideal input pressures? Or is there an easier solution to this?

Pic of the sexy offender