While having my rifle apart for leak repair, I could not resist making a small change. I added one thin washer behind the striker spring. This rifle was made using a Jack Haley PCP tube. Some of the work was porting and polishing the valve, removing the filter, screen, and pircing pen, and adding a new Delrin valve stem from Mountian air, I lapped this valve by hand until seal was made. I am using a stock striker spring and valve spring.
My rifle is a .22cal and I added a 24 inch Lother Walther barrel. I tuned this rifle to remove larger varmits, so power was needed, but I also wanted a decient shot count.
Using AOA 16 grain Pellets and a starting pressure of 2500 psi after 20 shots the rifle still had 1455 psi left. Here is the string.
Bill is that valve in Jacks tube yours or did Jack make it? The reason I ask is he made my valve and at 2500 p.s.i. mine topped out at 850 f.p.s. with 14.3's. I added my own valve in my gun and it hits numbers like yours. When I saw his valve it was smaller than a QB valve which would explain the max 850 f.p.s. no's. Benson.
George My rifle had a stock QB valve, with only the screen, filter, and pircing pin removed. The spring that Jack shipped, would drive a 16 grain pellet over 1000fps. The shot count had the gun empty after about 10 shots. I started cutting coils off the spring until I saw a velocity drop, then lightened the striker, this had me getting much better average speed, and better shot count. After about a year, the soft face on the stock valve failed, and I added a Delrin valve stem, that I bought from Mountian air. This brought the fps back up, so I put the stock striker spring back in and this last tear down, I added one washer to the stock striker spring to raise the center of the string at 2500psi starting pressure. Before 2350psi was my best starting pressure.
I got the idea of lighting the striker from scot laughlin, on this forum. And that was one of the best things I did to make a decient shot curve.
This message has been edited by Billcurtis on Sep 15, 2010 3:46 PM This message has been edited by Billcurtis on Sep 15, 2010 3:45 PM
Dave I never did weigh the striker, but I did grind off everthing in back of the sear ring, and ground down the front part of the striker in back of the front pin hole, to the same size as the smaller center section. My guess is about half the weight of the stock striker.
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