What numbers SHOULD I be seeing???
I think I’m stumped again.
I just installed an .22 cal Air Force 18″ barrel into my Talon SS and was fiddling with it. The gun is stock on the inside. The barrel was properly cleaned and prepped (polished breach) prior to use.
At 2800 psi fill and PW 9.1 I’m getting a five shot average of 888fps using Benji. Diabolo weighing in at 14.4 grain.
After much fiddling with the top hat from .070 to .085 Final numbers were created with the top hat at .085.
Lower power wheel settings are showing lower numbers.
The spring was changed out not that long ago as well. Oring have shown no signs of needing replacement AND I lubed with divers silicone prior to testing.
Anyone have any ideas? Suggestions or thoughts?
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???!!!
Are you saying that if I leave the top hat where it is and let the pressure of the gun go below 2000psi that I’ll get the same numbers with the PW at 0?
If so, how is that possible?
As your pressure goes below 2000, I think you’ll find that the powerwheel will drop to the 0 setting.
Interesting results.
MY gun is picky.
With a .075 TH and PW 9.1 with 14.4 Benji’s and 2700psi it gave me an average of 864. With PW 8.1 it was 830 ave.
With TH .100 and PW 5 it gave me Mid 600’s and with PW 8.1 it gave me 875 ave. With PW 8.9 I got 883 ave.
With TH at .085 and PW 8.9 I got the same (883) and with PW 8.0 I got 877 ave.
I was hoping to find somewhere that would give me close to 900fps with medium pellets without cranking up the PW but I guess more investigation is needed.
So far, .073 and PW at 9.1 gives me the highest speeds with Benji’s. I’ll be switching to Exacts soon and I’m sure it will all change…heheh.
It should do the same if your in the right place or close to it.
Dunno maw.
Kids are asleep. I’ll try it out tomorrow.
What do you get with tophat at .075?
After much more fiddling I think I’ve maxed out my set up.
With the TH set at .045 PW 5.9 and 2700 psi I was getting an average of 844 with Benji 14.4
With the TH set at .073 and PW 9.1 I was getting an average of 892 with them.
For giggles I dropped 5 Kodiaks at 21.2 over the chrony with about 2550psi in the tank and got an average of 806 for 30.6ft/lbs
That’s the best I can do that I’m able to see.
Seem reasonable or am I falling short of other folks stock setups?
Here’s what Airforce says about approximate expected velocities for a Talon with an 18″ barrel
(from left to right, approx. FPS for “light” pellet, “medium” pellet, “heavy” pellet)
Talon 18″ barrel, .22 = 1000fps 850fps 750fps
So if a 14.4g Benji pellet is considered to be “medium” weight, you’d be pretty much on spec, with your tophat adjustment maybe gaining you the extra 38fps or so.
But if 14.4g is considered a “light” pellet, then yeah, there’s something amiss.
Personally, I call “medium weight” anything from about the 13 to 16g range. For example, .22 CPs weigh 14.3g, and I’ve never heard anyone call them a “light” pellet. Obviously, we’re talking about a fine-line here, and others probably have different opinions…
Got any Kodiaks? We know for sure that those are “heavy”. If you do, shoot a few of those and see if they fall in that 750fps range.
Not sure if all this jabber helps or not… :wink:, but what kind of velocity were you looking for?
See the full chart here, http://www.airforceairguns.com/faqs.html
With the 18″ barrel you should be seeing speeds 90 fps higher than what you were getting with the 12″. So yes, something is wrong but I’m not familiar enough with the design of the guns to give you a diagnosis.
Hopefully another will come along to lend a helping hand!
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When the pressure drops the air does not come out as fast, and also there is not as much pressure against the hammer strike, the gun just comes to a point where its just doing all it can do.