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Air consumption with Altaros regulator. Good or bad?

February 16 2017 at 9:30 AM
JD  (Login JamesDingle777)

Allegedly set at 135 bar. Definitely spits JSB 18.1's at an average of 861 for 50 shots. I filled to 3K, shot 1 mag (10 shots) refilled and listened for when it clicked open (have a Hill MKIII) According to Hill gauge, (guns stays right at or slightly above 100 bar depending on fill. pushing it to 3200psi raises it ever so slightly between green and yellow, Rainstorm I model, I think reg leaks a little) So, according to Hill gauge, rifle uses exactly 400PSI per 10 shots.
I don't know tube CC size and I don't think 40psi per shot is the right way to define it. Even with a regulator, is 400psi per 10 shots good at 29.8FTLBS 861FPS?
This doesn't sound bad to me, 50 shots would take me from 3K to 2K. I've never had a regulated rifle though (this is a .22 Evanix Rainstorm I with Altaros) so I don't know if this is as good as it gets or not.
Have had rifle for about 3 days. I just filled to exactly 3K. Will let it sit for 7 days in same environment (check pressure again in 2 hours as I filled when cold from outside) and check to see if it dropped at all.
All help, advice is greatly appreciated.

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(Login BigTinBoat)

not too good, probably needs adjusting.....

February 16 2017, 10:03 AM 

Looks like the cylinder is 250cc in size. If you are getting 50 shots from 3000 down to 1450 the efficiency is under 1fpe/cuin.

If you just installed the regulator and made no other changes you are likely wasting air. A hammer spring that is adjusted to open the valve at 3K is WAY over powering the valve with just 1450psi (100bar) in it.

If your reg is set at 100bar (as indicated by the gauge) and you fill to 3000psi I would expect that you should be able to tune the gun to get 70 shots at that power level before falling of the regulator.

Now if the regulator is set at 135bar (your gauge off) then 50 shots from 3000 down to 1960 is right in line with expected results.

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(Login JamesDingle777)

I recorded a 3200K fill. 10 shots brought it to 2800psi

February 16 2017, 1:01 PM 

50 shots should be 1200PSI if all equal. The hammer spring plug is almost flush with receiver. One revolution in depth deeper. I also think spring was clipped because only one end is flat and ground.
I can see I'm going to need to send this to someone with a Chronograph, regulator tester and set it up for 21.1 5.51 Match Barracudas as they have the highest BC and range I'm looking for.
I knew too much preload is unnecessary as it's only going to do what reg is set at, right? More preload on a regulated rifle does not mean more speed, or does it?
Again, this is beyond me without equipment. I'll have to see who is willing to set it up at an affordable price.
I didn't install it. I bought it this way. it's very accurate and all his shots were 50 yards and under for hunting so it was fine for him. I'm desiring the most efficient, consistent, accurate long range with 21.1 Barracudas I can get. I'm even contemplating a 23.8 LW barrel for better efficiency.
Thank you.

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(Login lhd)

50 shots @ 40psi ea. would use 2,000 psi, right?

February 16 2017, 12:51 PM 

So wouldnt that bring you from 3,000 down to 1000? Normal guns don't get 29.8fpe at 1000psi. Any gun that gets 50 shots at near 30fpe is exceptional.

I think using a percentage of the reservoir volume used for the useful shot range is better than psi per shot, but many shooter DO use psi per shot, and if it give the info needed, so what?

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(Login JamesDingle777)

If I'm right, (which I very well may not be) this should be using 4.3cc's per shot; but

February 16 2017, 1:07 PM 

215cc divided by 10 shots is 21.5cc's so something is wrong. Any suggestions on an affordable adjustment & regulator rebuild?

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(Login BigTinBoat)

no need for a reg tester, just chrony

February 16 2017, 3:23 PM 

You have a chrony, right?

Fill the gun and shoot 5 shots recording fps.
Reduce the spring tension
Take 4 shots and record the fps.

Continue this sequence till your fps average starts dropping. Once it starts dropping then you are on the "knee" of the curve. This is about where you want to be tuned for best efficiency. If this fps is where you want to be then you are done.

If this fps is above where you want to be then you need to lower the reg pressure slightly and do the test again.

If this fps is below where you want to be then you need to raise the regulator pressure and repeat the test.

Of course if will get to a point (based on a lot of different variables like port sizes, valve volume, barrel length, etc) where raising the reg pressure will have no effect. At this point something else in the "equation" will need to be changed if you are not where you want to be.

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(Login JamesDingle777)

YOU are a helpful person, and I appreciate that immensely,

February 17 2017, 9:22 AM 

but NO, I don't have a Chronograph as of now. I owned 3, I shot 1, sold the other 2 when I got all my PCP's set up right, and all pellet data with spring guns and pellet combos written in journal.
I will buy another chronograph and find BC from 10 to 20 yards, not 25 to 50 and end up shooting one again. I know I need one to do stuff like this, set my first regulator, (thanks to you Robert, I now know how, THANK YOU SIR!) and to tell if a spring or seal is going bad on a spring gun. Yes, as meticulous as I am about shooting I definitely need another Chronograph. In the near future. You saved me $ Robert, thank you.
The only thing is the regulator should be rebuilt while out. And adjusting it requires disassembly every time, which stinks. It's time consuming and you risk nicks on o-rings every time. I'll get my o-ring set for gun and reg, buy a crony, chamfer everything, and get to work. Thank you again. I really appreciate when a fellow air gunner helps to teach the novice. You're a good Man.

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