but looks can be deceiving.
[IMG][/IMG]
Lets see. over the last month or so I've tweaked the AS2250 quite a bit.

1st: Upped the pressure behind the pellet to 1800psi.
2nd: Beefed up the hammer spring.
3rd: Made a 1018 steel hollow probe bolt and cocking lever.
4th: Put anti-friction rings on the striker.
5th: Beefed up all seals.
6th: Made a metal transfer tube.
7th: Made a Delrin poppet.
8Th: Made a 12" shroud.
9Th: Had Leupold change the scope parallax from 60yrds to 25yrds.
10th:Changed the scope rings to a medium from a low.
11th:Waiting for a Pacific Pelletguns two stage trigger to arrive.

End result, went from 685fps w/25.4gr pellet to 790fps with the same 25.4gr pellet. 35.2fpe! Not a leak to be found anywhere.

Very pleased with how everything turned out. Raising the optic really helped with allowing for a much improved cheek weld. Groupings are good now but should be great after the new trigger goes in.

Going to have to change it's name to the turkey tenderizer -at least until rabbit season opens.

Gobble. Gobble.

Im a fan of modding the XT. Mine's still CO2 but shrouded and hotter valve among other things. Have a Hawke AO scope on it. Curious about the metal transfer tube. Is that like the poly tube transfer port? What ID did you use please?

Be Well... Tom

"A fear of weapons is a sign of retarded sexual and emotional maturity." - Sigmund Freud

It took a bit of trial and error to get the length right. It's a compression fit between the breech and valve.

The ID is a #18 drill as is the exhaust port in the valve.

in mud. But it looks very cool, I like it.

S.W.A.G. it!

Is your new exhaust valve seal flat faced or tapered?

a 3/16 OD "nipple" at the barrel end. This extension is approximately .05" long. The barrel port has been drilled out to 3/16" and the nipple fits into that hole. As a result, the transfer tube effectively extends flush with the ID of the barrel bore.

I can't seem to get my rig above 20FPE in .22

I have a 1800psi tank like yours, poly transfer tube, B&A valve, discovery hammer spring (stock stryker) and a 2x" Discovery .22 barrel.

I get 20FPE

What am I doing wrong here?

[IMG][/IMG]

Moar info is greatly appreciated brother.
Joe Cortez.

Sick 'em H�f!!!

2010 Count
8 Crows/Ravens

the port in the B&A valve. I have the same valve and needed to drill it larger with a #18 drill bit.

Also, I changed the inner valve spring to an external style. There are posts on the yellow somewhere that show this.

Tons of brass can be removed from the inlet side of the valve as well. Increases volume.

The ridged transfer tube gave me a 20fps bump.

Getting the hammer spring strong enough to open the valve quickly took some fussing. I used a spring that I bought at a machinist supply store here in San Diego. It has a larger diameter than stock so both the striker and end cap had to be bored out.

Make a Delrin spring guide that slips inside of that spring. Keeps the energy going in only one direction.

The most profound boost in energy came from making a Delrin poppet and getting rid of the stock Crosman with it's mystery goo seal. At such high pressure, seems the poppet gets smooshed into the valve body. This translates into the poppet effectively taking longer to reach full open. The Delrin poppet opens crisply. It's important to get that poppet open as fast as possible.

Sorry if it's too much work but I'm in pursuit of your achievements

Thanks alot.
Joe Cortez.

Sick 'em H�f!!!

2010 Count
8 Crows/Ravens

short of opening the gun up again. It's so sweet right now I don't want to disturb anything.

Stay tuned.

http://www.network54.com/Realm/CFTech/Biovalveupdate.htm

Most of the valve mods came from here. The B&A port is already drilled at an angle, just needs to be a little bigger (#18).

The Boss valve is good but there is still room for improvement.

More to follow...

This is not the actual valve, but you can see what a Delrin poppet with the external spring mod looks like.
[IMG][/IMG]

were necessary on this AG because of the super strong hammer(striker) spring. The bolt would bind because of how hard I had to pull the cocking lever to cock the gun. It was wedging in the tube. Delrin rings made it slicker than deer guts on a doorknob.

[IMG][/IMG]

Here's one of the needed to be just a bit bigger/longer/shorter parts from my tuning project.

[IMG][/IMG]

It slips inside the hammer spring to prevent it from bending sideways.

If it seems to hit a wall of 20fpe then I'd check carefully for leaks. Use the tissue paper
over the breech technique. A leak can have a regulating effect, any more air only serves to
make the leak worse. Had it on a pumper with plastic breech flex.

I was curious what pressure you were running when I read an earlier post you did. I was getting 31 fpe with the 25.4gr pellets and the senior bigboy 28.6gr pellets and I had a leak at my TP seal. I took everything apart and made a new seal and now I'm getting 33.3 fpe on 1600psi and I'm very tempted to switch to 1800psi but I might wait a little since I'm building a shroud for mine which I'll post some pics next week. I'm stoked you passed my numbers but I'm a little jealous too! SWEET!

ain't nothin' to bark at!

I'd say you've done a very fine tune on that bad boy.

I was below your numbers until I made the poppet. That was the missing ingredient.

I'm wondering if 1600 might be near the sweet spot for the AS. Seems like I needed to do a heck of allot of mods just to squeak out another 2fpe @ 1800.

Great Job. I really like to see clean mods like that.

awesome.

ernie the eyeball