"Killzone"Update - I reassembled with a BStaley Tune - 3 #211 O-rings from True Value. I'm not sure if they are the 70 shore ones as they were not labeled so. I shot some strings and this is the best I could get with the hammer spring set at 6 and the hammer throw set at 2 and the valve full open.
I'm not pleased with the results - 690 down to 630 between 3000 and 2400 psi. Dan 25 - if I could get up to the mid 800, were you at, I'd be pleased.
I don't think the hammer is getting deep enough into the O-rings and if I increases the hammer throw any more the hammer striker may make too much contact with the valve that the hammer may not make contact with the O-rings at all - defeating the tune.
I think I need more spring rate or perhaps the O-rings are 90 shore. I just received my order from the O-ring Store so I have some 70 shore O-rings in there - I could try that as well.
My 16 shot string starts at about 830, climbs to 840 the falls off to 800 with 25 cal JSB Kings. I had to add a little more preload on the hammer spring and extended the striker to make up for the thickness of the O-rings. You should be able to get the velocity up with the striker adjustment. I just followed the youtube video posted by the kid with the sniffles. Shot a few groups for velocity, adjusted the hammer and added more spring preload. Got the velocity where I wanted it and said good enough for me. I'm sure I could improve on the shot count as others have got my tune beat. What I like about the Bstaley mod is my 3rd to 14th shots are +/- 3 fps and the limiting factor on accuracy is my ability, not the gun.
This is the vid I followed. I am sure there are others.
https://www.youtube.com/watch?v=flIxgQXC3r8