Consistency From standard A.I.R. valve

[Smokee_2_7]

How is everyone's velocity consistency with their standard AIR valves? This is of course assuming good paint, with the correct paint/barrel match.

The reason I ask is because I was some problems with one of my mags. Basiclly it just needed a tune-up. I was having some problems with reg. consistency. I went through the valve, replaced the reg seat 2 times (the first one was bad. . .) the Reg. piston O-ring, and the teflon o-rings in the on/ off assembly. Currently I am suffering from 2 problems:

1. velocity flucuations.

Over the chrono, slow, single shots I am seeing jumps of +/- 15 fps. Like i said, I suspected a bad reg. seat, but thats not the case. Could the reg. piston itself be the problem?

Additionally, I have never had any of my mags be very consistent over the chrono. I belive the best I have ever had was something like +/- 5fps. Not bad, but that could be a range between 280 and 290. I have owned other guns that were much more consistent.

Could the reg. spring and pin need to be replaced? It is very difficult to remove the spring- - -but the pin seperates eaisly from the spring. Even with a good dental pick its really hard to get the spring out from the assembly.





2. intermittent leaks down the barrel.

This occurs after SOME shots, when the trigger has been completely released. Normally i would chalk this up to a power tube spacer being too long, but this is a VERY faint leak, and is only every now and then. usually the best way to make it stop is to fire the gun again.

I am planning to try replacing the power tube oring here, and see if that fixes it. If now, ill go with a shorter spacer- - - but i went with this one due to bolt stick with a smaller one. I cant remember if that was the next size down, though. . . so I will have to play around with it.



Any suggestions are greatly appreciated.

Carl

[Butterfingers]

1) paint to barrel match is VERY important. You will never get good consistency without matched paint.

2) Pre-firing is BAD it leaks air out of the dump chamber reducing the amount of air that is to be releasedresulting in inconsistent velocities. Replace that spacer with a smaller one. If you are experiencing bolt stick check the length of your return spring. It should extend further than the face of the bolt.

3) check your firing points. When you pull the trigger SLOWLY until the sear releases and keep it at that point does it leak? Now release it SLOWLY. How much does it move forward until it recharges.

[Predater]

if you ARE USING CO2 THAT COULD AFFECT IT.(sorry about the caps.)

[Smokee_2_7]

Predater, Nope. I only use Nitro in all of my markers.

Butterfingers,

1. have my paint and barrel matched up as best as I can at this time. I am allowing for some of the inconsistency due to that, but the paint fits good enough and is consistent enough that +/- 10-12 fps. on the chrono is not acceptable.

2. I assume that Pre-firing refers to the occasional leak down the barrel. When I first put the current spacer in this marker, there were no problems at all. Thats why I want to try replacing the power tube oring first. If that dosent get it, Ill go back to spacers ( im just REALLY happy with the way the trigger feels right now. . . and would rather not change spacers unless nothing else works.

3. Will check the firing points on wednesday. ( Ive been leaving my guns at work just because I really don't have room for them here at school. . .) I will post back here with those results ASAP.


additionally, the trigger rod has NOT been adjusted at all.

What about the reg. pin, spring, and/or reg. piston? is it possible that one of these parts is defective? See my initial post for my observations on the reg. spring and pin.



Thanks for the replies so far. Keep 'em comming.


Carl

[unseenunheard]

-the reg spring could cause inconsistancies if it was out of wack, but if you really haven't messed with it much i doubt this would be the problem, so lets look at some other possabilities first.
-the occasional leak down the barrel could be several things ; 1st check the powertube o-ring, 2nd if it worked before with the spacer try a different bolt spring and even another bolt if you have one (if not i'll bring one out wednesday), 3rd if the sear is starting to get old and almost worn this could also cause an occasional leak, because if its just started leaking then something is wearing and needs replacing.
-the bolt spring being old and worn could also cause velocity fluctuations.
but again these are just some thoughts off the top of my head and if you want i'll help you get it straightened out wed. i'm sure that between the 2 of us we'll get it workin'

[Smokee_2_7]

Right now im tending to lean toward the reg. spring being a bit messed up. possible a bum reg piston, too. Well try replacing the power tube o-ring first, (for the leak). . .

Yeah, go ahead and bring out all your extra stuff wednesday. I doubt the sear is worn out, or the bolt . Both are fairly new.

Im sure we will get it rockin and rollin wednesday.


See ya then, paul

Carl

[PyRo]

Sounds like a reg piston. That is unless you have gotten a few bad reg seats, or have a bad paint-barrel match.