Why not make a lower pressure mag?

[TheTramp]

I've got to have 600 going into my valve with the med. spring in my L10.

Since as far as I know the AIR (and Retro) valve runs at ~400psi I would think you'd want at least 200 over that for good recharge. I don't see how it would work at 470. At the very best it'd have NO reactivity at all I'd imagine.

[the electrician]

I measured actual operating pressure, not the lowest pressure without shootdown.

I took an old powertube tip and tapped it 1/8" npt. put a line and a large gauge on it.(0-1000psi@2% acc.)

I got my classic to shoot a fairly consistent 280 with a freak barrel.

then changeed to the gauge set-up. it read 400 psi.

then I did the same thing with a lvl10 installed, using the standard spring. it measured 470 psi.

that's how I know. I'm not guessing.


nicad- I think that shows both ends of the pressure spectrum for the lvl 10 operation.
standard spring, @280 fps= 470
long spring, @ 300 fps = 600

[nicad]

There is even an easier way to do this...
no matter what valve you are useing-
Crank the velocity adjuster extra far in... well above 300fps, but within reason!! I use 330fps.
From your tank, run through a decent in-line reg (I like Palmers stuff) and from there tee off and run one air line to a good liquid filled gauge and the other into your mag as normal.

Start off with the in-line reg set low... then crank on it and watch you velocity as you shoot over a chrono.. once it hits 300fps (or 280.. whatever you are after).. what the gauge reads is what the chamber pressure is. walla.

Now, that tells us what the mag is STARTING off at... how do we find out how much pressure is left in the chamber after a shot? (Residue pressure).

That is why I drilled and tapped the air chamber of an X-valve to find out. VERY small air passage to the gauge to prevent adding any volume to the chamber volume.

What I found was pretty amazing.

Fire+hold trigger in (on/off is OFF, preventing air to recharge the chamber-- true for ANY mag). On my lvl10 with long spring running 600psi, the chamber read 200psi after a shot!!!
That is only effectively using 400psi, at .55ci. That should be 1200 FULL shots off a full 68/4500. Is that close to what anyone is getting?

ps. E- did you ever get those FS blueprints?


out!

[Duck Hunt]

Actually, now that you mention it, I get damn near 1000 shots on a 68/45 with a decently tuned level 10 setup.

Sean

[the electrician]

yikes, I get more shots than that, but there again, I use the standard spring and chrono at 280.

nicad- no I didn't, perhaps I need to tone down the e-mail virus scanner a bit. if you get a chance, please send it again. thank you .