Tuning How to get the BEST Accuracy out of an M3 Tune

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kaylaindy

kaylaindy

Member
Jun 3, 2017
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Washington, United States
Here is an example of how to get that last bit of accuracy out of the M3 after you have entered the factory suggested tune parameters. Each caliber and pellet will have a different set of numbers that serve as the "starting point" to tune the gun. 

This info is straight from the FX tech department. I followed what they said and my .22 M3 stacks pellets on top of each other at 70 yards. ..18.1gr pellets! 


So I had entered the factory tune numbers for 18.1gr w/ a 700mm barrel. They were:

3.1637237209.JPG


That made my gun shoot 930 feet per second. When I asked AGN how to tune it down to 890fps (pellet's best speed), I was told to "tune it to the curve of the knee". 

about a week later the FX tech Melissa told me "Feel free to tune the valve adjuster (front knob) down until you reach the desired velocity. You can turn it until you reach line 4. If you still need to decrease velocity, adjust the Micro wheel down one notch. 

.....BAM! I think this technique would aplpy to all calibers and ammo choices. For the recommended tune numbers just email FX USA at [email protected]


Her exact words (James also instructed me on this, hence the "line 4" info.)

The easiest way to slow the speed while maintaining consistency is the valve adjuster knob. Feel free to turn it in until you reach your desired speed.

If you start to notice sporadic speeds every once in a while you may have to back the valve adjuster knob off a little bit turn your hammer spring wheel down 1 notch and then readjust your valve adjuster knob. Just as a heads up in case this occurs you will already know how to address it.
Click to expand...


Here is the 25.39gr tune for the 700mm Sniper M3 Impact. I will get the tunes for all other pellets and calibers as I film my M3 video series, .22 up to .357. 

25.39grm3tune.1637236820.JPG



The first regulator should ALWAYS be set at 150 bar...that is across ALL CALIBERS from .177 to .357. Never shoot an M3 when it is below the front regulator pressure.

Here are default 2nd regulator settings. Happy shooting! 

m3defalts.1637236972.JPG



P.S. if you need to know how to properly adjust your M3, here is a 5 minute tuning guide:

https://youtu.be/ARAYrGq7iLs
 
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Great post! 

Though I'm pretty sure when the manual says: "Never shoot an M3 when it is below the regulator pressure" it means 2nd regulator.

And can someone please explain to me what "tune it to the curve of the knee" means in tuning an impact?
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Here's the deal. Take a glass of your favorite whiskey, and carefully balance it on your knee. If you can't shoot acceptable groups without spilling your whiskey, pour more whiskey and repeat. When you reach the point of satisfactory groups, or, when you no longer care, you have tuned to the curve of the knee. Let us know your progress.
 
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And can someone please explain to me what "tune it to the curve of the knee" means in tuning an impact?
Click to expand...

It's probably better if you don't ask that question. When I asked it on my original thread, that's when things went south. It's possible the people who told me that were just messing with me...but 2 people told me to do that...maybe they were friends. ?? My original question was "Which of the 5 knobs do you turn to go from 930-890 fps?" 

I think Melissa did a better job of explaining it. ...that's probably because women are smarter than men. ...just accept it. 


INFO ALERT: I was told yesterday by someone who would know, that the JSB Redesigned 25.39gr pellet is a unique pellet because it likes to fly 960-970 FPS

All other pellets like 880-900 FPS with maybe 10 FPS to either side. 


 
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I will try to explain it from my understanding and as simple terms as possible. These hammer operated airguns are what we used to call "balanced poppet valves". It is balanced because you are basically trying to balance the air pressure that comes thru the reg against the strength of the hammer strike that opens the valve. The valve is actually held closed by pressure, so if you increase the pressure from the 2nd reg here, then a properly tuned gun will actually show a decrease in velocity because the spring and hammer are not hitting hard enough to overcome the increased pressure behind the valve.

Tuning to the knee would be taking a set pressure and working your way up or down the hammer tension until it reaches a plateau (the knee). Come from the paintball world, we typically always worked up.....but airgunners seem to generally max everything and work down. If you are trying to make sure you are able to hit a maximum level of energy I can see that being the way to go. If you are tuning for moderate numbers or for pellets, my thought is to work up.

When you start low and work your way up in tension on the hammer (micro and macro wheels) you will hit a spot where velocity stops going up and further increases in spring tension will make the velocity drop. If you are in your target range for velocity, you can then back the hammer tension back to the plateau and then go about 5% past that down. That would put it at a lighter strike of the hammer and a more efficient tune as well. 

If you cannot get into your top end velocity target with where you are at with that reg setting, then you may have to increase the reg setting start again in finding your knee.



If I am incorrect in terminology or theory here, one of the real tuners can correct me.
 
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I will try to explain it from my understanding and as simple terms as possible. These hammer operated airguns are what we used to call "balanced poppet valves". It is balanced because you are basically trying to balance the air pressure that comes thru the reg against the strength of the hammer strike that opens the valve. The valve is actually held closed by pressure, so if you increase the pressure from the 2nd reg here, then a properly tuned gun will actually show a decrease in velocity because the spring and hammer are not hitting hard enough to overcome the increased pressure behind the valve.

Tuning to the knee would be taking a set pressure and working your way up or down the hammer tension until it reaches a plateau (the knee). Come from the paintball world, we typically always worked up.....but airgunners seem to generally max everything and work down. If you are trying to make sure you are able to hit a maximum level of energy I can see that being the way to go. If you are tuning for moderate numbers or for pellets, my thought is to work up.

When you start low and work your way up in tension on the hammer (micro and macro wheels) you will hit a spot where velocity stops going up and further increases in spring tension will make the velocity drop. If you are in your target range for velocity, you can then back the hammer tension back to the plateau and then go about 5% past that down. That would put it at a lighter strike of the hammer and a more efficient tune as well. 

If you cannot get into your top end velocity target with where you are at with that reg setting, then you may have to increase the reg setting start again in finding your knee.



If I am incorrect in terminology or theory here, one of the real tuners can correct me.
Click to expand...

This finally makes sense to me and thank you so much!
 
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I will try to explain it from my understanding and as simple terms as possible. These hammer operated airguns are what we used to call "balanced poppet valves". It is balanced because you are basically trying to balance the air pressure that comes thru the reg against the strength of the hammer strike that opens the valve. The valve is actually held closed by pressure, so if you increase the pressure from the 2nd reg here, then a properly tuned gun will actually show a decrease in velocity because the spring and hammer are not hitting hard enough to overcome the increased pressure behind the valve.

Tuning to the knee would be taking a set pressure and working your way up or down the hammer tension until it reaches a plateau (the knee). Come from the paintball world, we typically always worked up.....but airgunners seem to generally max everything and work down. If you are trying to make sure you are able to hit a maximum level of energy I can see that being the way to go. If you are tuning for moderate numbers or for pellets, my thought is to work up.

When you start low and work your way up in tension on the hammer (micro and macro wheels) you will hit a spot where velocity stops going up and further increases in spring tension will make the velocity drop. If you are in your target range for velocity, you can then back the hammer tension back to the plateau and then go about 5% past that down. That would put it at a lighter strike of the hammer and a more efficient tune as well. 

If you cannot get into your top end velocity target with where you are at with that reg setting, then you may have to increase the reg setting start again in finding your knee.



If I am incorrect in terminology or theory here, one of the real tuners can correct me.
Click to expand...

Also, tuning to the knee will take care of minor regulator inconsistencies. 
The idea is the have the perfect hammer weight for said valve/reg pressure. You will hear the rifles report completely quiet down. And once u get used to it…you wouldn’t be able to stand a pcp that’s not tuned. 


 
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The first regulator should ALWAYS be set at 150 bar...that is across ALL CALIBERS from .177 to .357. Never shoot an M3 when it is below the front regulator pressure.

Click to expand...


Kaylaindy, I question your statement above. I was told by my dealer to never shoot my M3 when the tank pressure is below the SECOND regulator, the one closest to the pellet probe. Please clarify your statement.
 
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The first regulator should ALWAYS be set at 150 bar…that is across ALL CALIBERS from .177 to .357. Never shoot an M3 when it is below the front regulator pressure.
Click to expand...

Kaylaindy, I question your statement above. I was told by my dealer to never shoot my M3 when the tank pressure is below the SECOND regulator, the one closest to the pellet probe. Please clarify your statement.
Click to expand...

m3manual.1637522248.JPG


it's on page 9 in your M3 manual. Don't fire the gun below Reg #1

...or reg #2...ANY reg! 


DID YOU KNOW? Never fire the Impact when there is no air in the gun, this will damage the gun and it will not be covered under the warranty. You can fire the gun with the bottle off to get the last bit of air out of it...but don't fire it after that. 
 
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Kaylaindy,

Below was an email I sent to my FX dealer:

”The manual says not to use rifle if tank pressure falls below the “regulator” pressure but it doesn’t specify “which” regulator. Can you clarify which regulator, 1st or 2nd?”

and the dealer’s response:

“It would be your second reg. The one by the pellet probe.”

So, are you saying the dealer is wrong?
 
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You can shoot a Maverick below the first reg down to the set point of the 2nd reg why is the m3 different
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The Maverick is a Wildcat with added features to bring it to the performance of an Impact. An Impact is just an Impact. They are totally different guns. The only similarity is they look kind of the same.
Click to expand...

And they both have 2 regs
 
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