wow so i have a CA M15, and it was shooting like 200fps stock lol. Now I had heard the seals suck on them, but i didnt think it was TERRIBLE. So I went to put a PDI 170 in tonight and when I took the piston and clinder out, i could just drop the piston through the cylinder with no friction between them. the piston barely even touched the cylinder walls!! I took my stock marui AK piston head and put it on the CA piston and used a stock marui cylinder and that seal made a world of difference, the compression would not let any air pass when i pushed on it. So basically if you have a CA rifle and want to upgrade, a simple spring and bushings wont do it. Get a new piston head and cylinder with it. it makes the rifle redeemed.
yea i lubed it after upgrading the pistonhead/cylinder... lube wouldnt have helpped how bad the stock one was...
Well, just another reason to get a TM (waitning for someone to jump me on that....)
You could always go cheap and just get a slightly larger piston head O-ring. Or do what I did & stretch the CA O-ring by hand.
Ya, Glen had the same problem with mine. We couldn't figure out why the fps was so low with an M120... He threw in a bore-up kit and bingo--410 fps.
LoL i told fools that...CA piston heads have no seal after about 3-4 months of play...i put stock marui piston/piston heads in there to make sure youll get proper seal.
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yuck..so what's the dealio? their o-rings shrink?
i think so, the gun started at like 300 fps, then maybe 2-3 months later it does like 250 fps now its been like 6 months since i bought it and it was doing like 200fps stock at a yuba cqb game like 3 weeks ago. i guess they shrink. that marui piston head and cylinder made such a difference.
