[Dragon235]

I've got a buddy's Tippmann A5 that was a bit beat up and needed a bit of TLC. After breaking it down and cleaning 3 years of grime out of everything, replacing some missing pins, all of the orings, and the missing velocity screw, the marker refused to chrono over 225-230. After subsequently replacing the rear spring, the marker's highest reading I could get over the chrono was 240.

The only thing I noticed out of the ordinary was that I did not locktite the velocity screw in and it turned really easily- more easily than I've ever seen on an A5- I'm wondering if this may have something to do with it and it needs a new powertube? I didn't notice any cracks or anything, just the really loose velocity screw.

Any ideas?

[FreeEnterprise]

Your powertube either needs new o-rings, or just needs cleaned.

Here is a video (not mine) that shows how to do it.

[jweav151]

Try turn the velocity screw in more. Usually turning it out increases velocity, but if you turn it out too much you create a void in the side of the power tube where air can get hung up instead of flowing freely out which will lower velocity.

[caw88]

I had a A5 that no matter what I did it would not fire above 240. I was using a flatline so it wasn't really a big deal but I changed everything in that marker for the better part of 7 years. I finally traded it away. My best guess was the body halves were warped and allowing air to escape, or the internals which were polished were no longer creating a good seal around the bolt. It shot great...just not 280 fps.

[Bigjoe11]

If all else fails, cut down the valve spring a little. It doesn't have a zero kick hammer, does it? That could cause low velocity.

[grss429]

Originally Posted by Bigjoe11

If all else fails, cut down the valve spring a little. It doesn't have a zero kick hammer, does it? That could cause low velocity.

Thats a stupid idea...

If the gun isn't reaching above 240, there is only 3 things that could go wrong..


A:Your power tube is wore out
B:Your power valve is wore out.
B: Your rear drive spring is bent/been cut down

http://www.pbnation.com/showthread.p...3#post74334473

[demo11x]

^^ i agree. my guess would be a wore out power tube/valve. wouldnt be a bad idea to go ahead and replace the power tube. they arent that expensive. since you are replacing that, a new bolt isnt a bad idea either. you can find them for about $40 for the pair. imo i would upgrade the internals

[Guy In Digi Camo]

slather some DOW 55 on the o-rings see if that works

Just get some replacement parts
Email Tippmann service, they might send you some replacements for free + shipping if they are in a good mood, happened to me