Low ball velocity. Help.

Hello.  I have a Tippman M-98 with a 32 Degrees 6 stage expansion chaber and a 15 inch Angel Force Barrel.

I have both CO2 and Nitro tanks and have fired them through the gun.

The problem is:  Im getting very low ball velocities and a lot of drop.  I screwed the velocity adjuster in as much as it can go, and out as much as it can go. 

Im also having trouble hitting things with relative accuracy at 25 feet away.  Rentals are doing better.

I tried with my flatline, my original barrel, and the current one, but they all shoot crappy.

Both CO2 and Nitro dont seem to help.

What can i do to fix this?

skrip00 wrote: Also, im missing one of the left side valve screws... Ive never removed those before, I cant find where it went, but its gone. EDIT:  Its not stripped, but its missing

Likely that you are loosing pressure out the screw hole, but also, have you ever changed the drive spring (the spring that makes the hammer/rear bolt hit the valve. A weak spring will lower the velocity...just like having a rear adjuster on your marker. Mopre pressure from the spring, higher velocity; lower pressure from the spring, low velocity.

But first, replace that screw in the side of the valve chamber. That alone may fix it.

skrip00 wrote: Ok, thank you. Also, what do i need to fix when i hear gas coming from the barrel?

its propbally a bad o-ring.

One missing screw may allow the valve to move when struck by the hammer, but! Even though the screw does not go through into the chamber, the fact that it no longer holds the valve chamber tight against the inside of the gas tube pressure can allow pressure to leak out the screw hole by going between the valve and the tube. Not much, but enough to lower the pressure and reduce ball distance. I fixed just such a situation in a 98C marker. The single screw that was still present was holding the valve body very well so the hammer was still opening the valve completely. Just a little less gas was making it to the ball.

But a weak spring is still likely the short ball flight culprit.

Edited by Bruce A. Frank

To add to what Bruce said. The powertube doesn;t fit super tight inside the body. Thats what those screws are for. Missing a screw the valve can shift slightly, causeing the rear bolt to hit it at a slight angle and slowing down the bolt.

I also never thought of air escaping from the screw hole that way. Thanks Bruce.