GTA
All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Long_Gun_Dallas on February 20, 2020, 03:14:38 PM
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Another member had pmd me about modifying his pp800, so I took mine apart to guve him some illustration.
My Bandit was the first pcp I ever used or aquired. The price point was just too good for anything else I could find on the market comparable.
When I got it, I lightened the hammer, cut the hammer spring, and threw a shim in there to keep the spring guide from being loose in there. Loose means sometimes it would seat in its place, some times it would not, creating variating spring pressures.
I also threw a huma regulator in it orginally, but the plenum it came with took up a huge amount of volume. Current calculations with no plenum show I have 36 maybe a hair less cc available. The plenum is 8cc. Also, the valve body used to be longer. So 22cc air tube? No Thank you.
The valve body was cut back, and I cut an oring seat into its face by hand. So the regulator seals directly to it.
When I disassembled it yesterday, I hogged out the inside of the valve body a hair more, and smoothed a sharp ledge inside it. Where there used to be an oring (regulator has to vent, so it is gone).
Regulator is set at 100bar. Shot count was 50 at 650fps with 8gr wadcutters. My target velocity. But I picked up another 30fps yesterday, so I removed the shim from the hammer. All my hammer bounce left! And I still had 670fps. I cut the spring some more. 660 now. I epoxied the spring guide to the end cap so it has nowhere to go. Roughed up the mating surfaces pretty good, so it will take something special to dislodge it.
The gun is 3x quieter! Holy smokes! I didnt think pistols could be this quiet! Wish yall could hear it, haha.
+velocity +efficiency -report
All because I was helping someone else. 🙂 I'll take it.
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Do I hear 60 shots now?
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I'm actually at 48, haha. I thought it'd be more, but I guess the 10fps is still enough to overcome whatever loss hammer bounce caused. 48 is still a lot. I may turn the regulator down a hair, though.
To be fair, the gun was shooting 670fps. But also 660. There were two types of pellets in the tin. The crosman 7.4s shoot slower 🤔