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nicklenn
06-15-2008, 05:50 PM
So I got bored today and ended up with the carbide bits and dremel in my hand. End result was halfbacking and putting my striker on jenny craig. Got it down to 40grams. I'm curious on which way I should head with my spring settings. I can't test the gun until tomorrow so I figured I'd see what you guys thought as I'm not quite sure which one to change first. Current settings are below and when I played yesterday it shot amazingly. Any input is greatly appreciated.

Pilot ACS
Stock bolt
Drilled stock valve
Modified stock valve pin
32* VA
PMI regulator
32* spring kit. (strong valve, weak main spring)
285fps at 450psi

Sandman_Bravo
06-16-2008, 04:00 AM
Go as light on the valve spring as possible without the cupseal leaking (this will allow a lighter hammer to strike it open longer for higher dwell & flow) and then chrono/tune the mainspring to match. By lightening the hammer you achieve less inertia and weighted mass in motion. This shortens dwell (the amount of time the valve is open) and reduces recoil for a smoother shooting gun. By keeping the main spring as light as possible, it maintains the less recoil/smoother shooting agenda. This is the reason for a light valve spring; so the lighter main can still gain proper dwell time.

nicklenn
06-16-2008, 06:26 AM
Go as light on the valve spring as possible without the cupseal leaking (this will allow a lighter hammer to strike it open longer for higher dwell & flow) and then chrono/tune the mainspring to match.

ok, i'm following you there. that was kind-of my hunch but i wasn't positive. see i'm kind-of at a wierd spot now until i get a new regulator. my PMI regulator (which was given to me so that's why i'm running it for now) won't go below 450psi. if i try and go any lower than that it will just shut all air flow off. i'm assuming it's due to it being a cheaper regulator? i thought about messing with the spring inside or even opening up passages but i don't want to risk screwing it up until i've got a new one here and ready. i've done enough internal mods now to the gun to increase flow that i almost couldn't get my chrono down enough to play on saturday even with the lightest main spring. so if my thinking is correct... until i get a new regulator that will allow a lower operating pressure i should keep the stiff spring on the valve to cut dwell down since i can't go lighter on the main spring. correct? i'll hopefully be getting a palmers here shortly so i should be able to drop down into the 200's for pressure. i'm still stumped why that PMI won't go any lower.

nicklenn
06-16-2008, 07:34 PM
nevermind on that last one. got it figured out. did a little research and found out there's a removable shim inside the regulator. once removed it drops the pressure range down to 250-575psi. i pulled that out and readjusted the gun. currently i'm at 375psi, medium valve spring, stiff main spring, and 285fps. anything below 350psi and the regulator won't recharge quick enough to keep up with 13bps. i'm happy with it now. eventually i'll upgrade to the palmers but it seemed decently consistant with the PMI. not too bad i guess with only modified stock parts, a regulator, and a spring kit.

Sandman_Bravo
06-16-2008, 08:02 PM
Sounds great! Actually, anything lower than normal pressures (800 psi) is low pressure. Some people may find the sweet spot of optimal gas efficiency and performance at maybe 500 psi and some may find the best setting at 250 psi or less. Every marker and set-up is different. For me, I was able to lower to under 275psi before encountering re-cocking (burping) issues but efficiency was awful. I settled in at 350-375psi as my best efiiciency and performance setting.