3000 psi tube QB78

[SeanMP]

I would try it if I was in the position of just wanting to change the valve spring. The o ring will stay in position on the retained half. Just don't move the gun around and let the poppet fall out

[rsterne]

Following the shot it sounds like i have a load of air traveling through the barrel after the pellet has left.

If you can actually HEAR the air escaping separate from (ie after) the sound of the shot you definitely have a problem with the valve hanging up.... Even with the lightest of valve springs, the air pressure should shut the valve with anything like 1000 psi in the gun.... I'm guessing maybe you bent the valve stem or it's got some dirt/chips making it drag.... On PCPs, I have found them to be relatively insensitive to valve spring changes, but VERY sensitive to hammer spring changes....

Bob

[remtom1200]

After adding a little more preload to the valve spring this afternoon I pumped to 1800psi and listened carefully as I shot. Valve is staying open too long and I do believe what I am hearing is the echo of all kinds of expanding air coming from the barrel. I also believe what your saying rsterne is true about the hammer spring and I got too excited to add a spacer of 3/16 before trying it without. You know it sounds like i am shooting with a 10ft piece of 2'' pvc pipe on the end of the barrel along with the crack. Now if only there was an easy way to pull that spacer without disturbing the breech seal and barrel o-rings.

[SeanMP]

I pull mine apart all the time and reuse the breach seal and Orings

Did you do some deburring while you had it apart...I'm guessing yes

[remtom1200]

I did smooth everything out pretty nice. Think I should make some pretty brass end caps while it is apart. Caught myself reaching for the end of the barrel tonight....hard habit to "break"...lol

[SeanMP]

Bling would be nice

But this would be nicer


http://www.airgunhome.com/agforum/vi...586&highlight=

or this if you like lower tech

http://www.airgunhome.com/agforum/viewtopic.php?t=7459

[AirGunEric]

I did smooth everything out pretty nice. Think I should make some pretty brass end caps while it is apart. Caught myself reaching for the end of the barrel tonight....hard habit to "break"...lol

I got some real "bling"available- nickel/chrome coated QB barrels and breeches- nice silver look to them. No time to put them online, however.

[SeanMP]

Booooo Yaaaaaaa



Al is gonna pee hisself

[remtom1200]

I need to see these Eric!

[remtom1200]

well SeanMP you just had to show me those links, and Eric your being a tease...LOL! I'm sitting here with my QB in parts, just put the valve spring back closer to factory, and undecided on that spacer for the hammer spring. If I remove it will there be lockup, or if I put it in the lathe to take a little off? Maybe I should leave it and lighten my hammer a little? I feel as though I should be wasting less time wondering and making one of those power adjusters, that is a thing of beauty!