Author Topic: Air Force Bell Curve  (Read 588 times)

sixshootertexan

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Air Force Bell Curve
« on: April 25, 2018, 06:04:58 AM »
I'm working on a AF rifle for a friend of mine. Does anyone know what the bell curve should look like on a stock .25 Condor? I'm looking to have an average velocity of 950. Hoping to not have to shoot a tin of pellets to figure this out.


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rsterne

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Re: Air Force Bell Curve
« Reply #1 on: April 28, 2018, 09:59:43 AM »
I have seen a lot of threads where the owners of AirForce PCPs vary the power wheel setting as the pressure drops to extend the bell-curve.... I am also curious about the curves, with and without doing that....

Bob
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sixshootertexan

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Re: Air Force Bell Curve
« Reply #2 on: May 01, 2018, 09:36:23 AM »
Yea I had his rifle apart. I put it back together and set the power wheel to around 3 1/2 and it shot at 850fps. Moved the wheel up a little and hit 950 just like I was wanting. Next shot was 980, next shot after that was 1050. I tinkered with it awhile and it kept doing the same. Dial it down and a few shots later right back up to 1000+. I'll just give back to him and let him set it where he wants it.
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Bullfrog

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Re: Air Force Bell Curve
« Reply #3 on: May 01, 2018, 07:21:21 PM »
I bought a used 2016 .25 Condor last year. I've learned a lot about the platform as I've experimented with the gun.

The age of the Condor makes a big difference. Newer Condors made since the release of the Escape use the Escape's internals and make 100fpe out of the box. My gun is one of those newer Condors and its impossible to tune for 25grain JSBs under 1000fps even on the lowest power wheel settings without making some other changes. If using the factory tophat, I have to add an oring under it. If I use a Talon Tunes topcoat, I have to add a restricter screw. With either of those two minor modifications, I can tune pellets for a range of velocities under 1000fps.

Right now I have the gun tuned for the 25 JSBs with the Talon Tune tophat and the largest restricter screw in place and the power wheel set to just under 4. My tune starts at 2500psi and I get dozens of shots starting in the 850s to 860fps between 2500psi and 2000psi. I'm impressed with how efficient the gun is. It wasn't something I expected out of the Airforce guns because of the unconventional way the valve and hammer works.

I'd be curious to know how accurate the gun is being for you. My gun at 100fpe is very accurate with heavy swaged bullets on a 3000psi tune, but I about pulled my hair out trying to get it consistent with pellets. The velocity didn't matter. Whether 1100fps or 800fps, I was spraying every pellet I tried. I made several changes to the gun that all helped a little such as replacing the worn out breech and using very tight clamping rails for my scope and giving the very dirty barrel a good polish. But the gun didn't become a tack driver with pellets until I started setting my pellet tunes at 2500psi and under. If I start my curve at 2500psi or below, it shoots pellets very accurate and consistently. Above 2500psi, they spray. Bullets, on the other hand, don't seem to be pressure sensitive. 

Either my gun is a fluke (remember it was used when I bought it), or the Condors, especially the more powerful versions that are moving more air, prefer to shoot pellets at lower fill pressures.
« Last Edit: May 01, 2018, 07:25:12 PM by Bullfrog »

rsterne

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Re: Air Force Bell Curve
« Reply #4 on: May 01, 2018, 09:27:14 PM »
It would seem to me that if the 25 gr. Kings are too light, the gun might be stellar with the 34 gr. King Heavies.... Just a thought....

Bob
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Monkeydad1969

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Re: Air Force Bell Curve
« Reply #5 on: May 05, 2018, 11:08:30 AM »
AirForce has been making the valves a lot more powerful and more efficient from what I have recently experienced.  May you should look into the new AirForce Ring-Loc Valve Pin Cap Kit for Condor/Condor SS.  They will also work with the Escape.  All the new Condors and Escapes come setup to use the new system.  So if you have any models from last year and back, you'll need to order a new tophat.  But I have been talking to some of AF's guys and the new system is great.

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Bullfrog

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Re: Air Force Bell Curve
« Reply #6 on: May 05, 2018, 12:35:49 PM »
AirForce has been making the valves a lot more powerful and more efficient from what I have recently experienced.  May you should look into the new AirForce Ring-Loc Valve Pin Cap Kit for Condor/Condor SS.  They will also work with the Escape.  All the new Condors and Escapes come setup to use the new system.  So if you have any models from last year and back, you'll need to order a new tophat.  But I have been talking to some of AF's guys and the new system is great.

Joe

I just checked it out. In principle it looks like the same thing TT and some other aftermarket providers have been doing, providing a way to restrict or open up the flow from the tophat. I do like having a range of actual different tophats to chose from instead of having restrictor screws going inside one single tophat. I've already lost all my restrictor screws for my TT tophat except one.

Monkeydad1969

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Re: Air Force Bell Curve
« Reply #7 on: May 06, 2018, 07:52:11 PM »
AirForce has been making the valves a lot more powerful and more efficient from what I have recently experienced.  May you should look into the new AirForce Ring-Loc Valve Pin Cap Kit for Condor/Condor SS.  They will also work with the Escape.  All the new Condors and Escapes come setup to use the new system.  So if you have any models from last year and back, you'll need to order a new tophat.  But I have been talking to some of AF's guys and the new system is great.

Joe

I just checked it out. In principle it looks like the same thing TT and some other aftermarket providers have been doing, providing a way to restrict or open up the flow from the tophat. I do like having a range of actual different tophats to chose from instead of having restrictor screws going inside one single tophat. I've already lost all my restrictor screws for my TT tophat except one.

Glad I can help.  I'll be getting a set for a "special" build.

Joe
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Bullfrog

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Re: Air Force Bell Curve
« Reply #8 on: May 08, 2018, 11:31:34 AM »
Disregard my speculation concerning the Escape/new Condor internals being sensitive to pressure for pellet tunes. My valve was slightly unscrewed. It would have came that way from the fellow I bought it from. Now that I've found that issue and corrected it, the gun seems to group pellets tight at any fill pressure.

sixshootertexan

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Re: Air Force Bell Curve
« Reply #9 on: May 08, 2018, 12:03:54 PM »
My friend tested his yesterday and was very pleased with the grouping at 50 yards. He also said the shroud I made for it really made it quieter than the Mac1 brake that was on it.
CCS 2300, CCS 2400, Custom Built Regulated .25, Custom Built PRod Clone, .308 Bullet shooter, XS46U .177, Custom regulated .177, 850 Hammerli .177