xvalve first shot drops

[fhawkeye]

Check to see if your rail bushing is in place. yes

When it is leaking, can you stop the leak or slow it a bit by pushing back on the tip of the bolt. No- see below

Also, if you use a carrier size that is too tight, the leak might not go away, because the tight fit of the bolt stem pushes the oring back rather than allowing the bolt stem to fully move the vent hole past the oring. retuned it from scratch

Check the sear for wear. A worn sear will allow the bolt to sit too far forward. Brand new sear because old one snapped in half after 7 years

Check your bolt stem to see if it hasn't come loose. They are press fit, but sometimes come apart. This is rare but has come up a few times recently. no but good to know thats a thing

Are you sure the leak is the powertube and not a leak in the chamber where the powertube screws onto the valve body, or a leak between the front and back half of the valve.

The more I dug through it the more I started to believe it is in fact something with the on/off. Picked one of the on/offs I was using tinkered with it a bit, no more leak.

I then re-tuned the level 10 properly and any leak was changing pitch between the carriers (I noticed that the leak wasn't changing between carriers originally)

I guess I was thrown through a loop because holding the trigger stopped the leak which always meant to me it was a power tube issue.

I can't certainly say for sure if the velocity issues are solved as I don't own a chrono but the first shot just sounds more consistent with the rest (originally you could tell the ball would just 'bloop' out followed by darts.)

But I'm comfy closing this out for now. Thank you all for the suggestions! I'll be able to check for sure this weekend!

[nak81783]

What you're now describing sounds like either the middle or bottom on/off oring. Leak stops when you pull and hold the trigger, because the chamber dumps on the pull and can't refill due to holding the trigger back. I.e., air can never leak past the aforementioned orings. However, when allowed to refill and sit for a while, pressure has been lost through one or both of the aforementioned orings. I'm not sure how low the dump chamber has to get before the reg opens back up to refill it, but it's feasible it could drop enough to lose 50 or so fps before refilling, probably more so if you've got something wrong with reg valve assembly or reg seat orings.


Glad it's working.