Just to add some extra beans to this thread that rallyshark created. Here goes some more. I do not have a peek poppet but a nylon one. My valve seat is 6.85 and my hammer weight is made of tungsten carbide and around 21grams with a stainless steel spacer that combined make about 6mm pre tension. Made a brand new stainless valve pin with reduced diameter of 2mm around the valve seat segment instead of 2.75mm. i use a 800mm barrel and a single 500cc bottle. Using for the .22 an fx pin probe and a stock hammer spring. Return spring i am using is 6mm OD x 0.3mm thickness by 15mm lenght. Since i run the gun from 15 grain pellets to 40gr slugs i needed a lot of adjustment in the hammer wheel so made a 20 position with 0.35mm increment one that uses the full travel of the adjustment screw at the back. For fine tuning created a valve return knob like the impact has.
It is using a plenum with 146cc.
Polished reg piston and screw for consistency although it remains sensitive to temperature change since it is still the plastic one.
My prefered reg pressure is 125bar for target shooting at close to medium ranges (up to 300m) shoots 30gr at 1010 or 40gr at 915 (bc is the same as higher speeds).
At 170 bar shoots 40gr at 1025
At 185bar shoots 40 gr at 1105-1110 (109ft/lbs) so the receiver is the limiting factor for longer slugs. (If anyone knows a supplier with heavier quality slugs please tell me.)
If i use it for bench the longer bottle location is definitely a plus for stability with the added plenum section.
If used in standing position you can remove the extra reg section and place a 600mm barrel and go for it. 990fps with 41gr slugs in .25 tested at 170bar.
Thanks to rallyshark for inspiring me with this great post ,
and the modding will continue.
Cheers
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