FX What is a Good 25.4gr Tune? (FX Impact M4 .22 700mm)

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kaylaindy

kaylaindy

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Jun 3, 2017
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Washington, United States
My 700mm FX Impact M4 came tuned for 18.1gr pellets at 2.5 Micro Wheel and 90 bar Reg pressure. (Line 4 Valve Adjust) I'm not going to touch the valve but does anyone have a good tune to bump up to the 25.4gr pellets?

Should I just turn the Micro Wheel up untill they are flying 890-920 FPS? or would I change the Reg Pressure too? Any advice would be welcome.

M3 owners please share tunes too because the M4 is pretty close.

Thank you!

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I would start by bumping the micro up a little and see if you get a velocity increase. That will tell you if you need to bump the reg pressure up or not. If you don’t get any more velocity with the micro then bump the reg to 95 and repeat. Find that plateau where you get no more velocity for a given reg pressure until you hit your target velocity. I think you are correct at going for that 910-920 range. Guessing you will most likely have to increase reg pressure probably ending up around 100. I always prefer to get just about to the point with the micro where no velocity increase happens before bumping the reg up.
 
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Trucker3573 said:
I would start by bumping the micro up a little and see if you get a velocity increase. That will tell you if you need to bump the reg pressure up or not. If you don’t get any more velocity with the micro then bump the reg to 95 and repeat. Find that plateau where you get no more velocity for a given reg pressure until you hit your target velocity. I think you are correct at going for that 910-920 range.
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Oh. That's how that works. Thank you so much! That helps me understand alot. ...and I'll go for the higher 910-920 range.
 
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They (micro and reg pressure) work together. Generally work them up together and down together. Looking for a harmonious balance between the two. That harmonious spot for a given reg pressure is right about or just a tad under where increasing the micro gives no more velocity increase. Work in small increments so you don’t shoot right past that point. The trick is to get the reg pressure which gives the velocity you want at this nice balance point.
 
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In Earnest Rowe's video he suggested setting the Valve adjuster on 4, the Macro Wheel at 8 and the Micro Wheel at 3 as a starting point. My .25 Standard M4 came tuned for 25.4 grain .25 pellets. The Regulator is set to 100 BAR, the Macro Wheel was set to 16 and the Micro adjuster was set to 4.5. It's shooting the 25.4 grain FX pellets at 923 FPS. It seems they all come from the factory set to 16!
 
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FLgunner said:
In Earnest Rowe's video he suggested setting the Valve adjuster on 4, the Macro Wheel at 8 and the Micro Wheel at 3 as a starting point. My .25 Standard M4 came tuned for 25.4 grain .25 pellets. The Regulator is set to 100 BAR, the Macro Wheel was set to 16 and the Micro adjuster was set to 4.5. It's shooting the 25.4 grain FX pellets at 923 FPS. It seems they all come from the factory set to 16!
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I deleted my previous post because my information was not directly from an FX employee. It was from an FX dealer in Sweden, and none of his M4s were delivered from the FX factory set to 16.

Did you receive your M4 directly from FX Sweden?

If not, did your dealer set the tune for you?

I tune my M3 as taught by Ernest Rowe and Viking Airgunner.

Now my .177 is tuned to less than 12 fpe for a 9 grain H&N FT pellet. My macro is at 6, micro at 2.5 and the air valve at 3.

I open the macro to 16 it moves the micro to 4 + and can be reduced down to only 3 and I end up at 15.7 average fpe. I would have to throttle the air valve below half open, so 16 cannot be a default setting.

My 30 cal is tuned to < 80 fpe for the FX 44.8 grain pellet and again setting the macro to 16 will require me to lower the plenum pressure or throttle the air valve more than 50% closed to hold < 80 fpe.

My current tune is fine out to 70 yards. If the current pellet doesn't perform well past 70 with this tune I will drop pellet weight and adjust the micro and macro as the gun was designed to do for different pellet weights.

80 fpe is the max power limit for our EFT targets.
 
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Troy Bakel said:
I deleted my previous post because my information was not directly from an FX employee. It was from an FX dealer in Sweden, and none of his M4s were delivered from the FX factory set to 16.

Did you receive your M4 directly from FX Sweden?

If not, did your dealer set the tune for you?

I tune my M3 as taught by Ernest Rowe and Viking Airgunner.

Now my .177 is tuned to less than 12 fpe for a 9 grain H&N FT pellet. My macro is at 6, micro at 2.5 and the air valve at 3.

I open the macro to 16 it moves the micro to 4 + and can be reduced down to only 3 and I end up at 15.7 average fpe. I would have to throttle the air valve below half open, so 16 cannot be a default setting.

My 30 cal is tuned to < 80 fpe for the FX 44.8 grain pellet and again setting the macro to 16 will require me to lower the plenum pressure or throttle the air valve more than 50% closed to hold < 80 fpe.

My current tune is fine out to 70 yards. If the current pellet doesn't perform well past 70 with this tune I will drop pellet weight and adjust the micro and macro as the gun was designed to do for different pellet weights.

80 fpe is the max power limit for our EFT targets.
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I purchased from The Pellet Shop, I did not pay extra for a tune, so I assume they just did a basic function test before sending it out the door, thus how it was set up was from the factory. I recall reading somewhere that all FX shipments are sent to UA now and then distributed to the other vendors, but don't take that as Gospel. But even if that is how they get distributed, I really doubt UA would open every box received prior to forwarding it on to a vendor.
 
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FLgunner said:
In Earnest Rowe's video he suggested setting the Valve adjuster on 4, the Macro Wheel at 8 and the Micro Wheel at 3 as a starting point. My .25 Standard M4 came tuned for 25.4 grain .25 pellets. The Regulator is set to 100 BAR, the Macro Wheel was set to 16 and the Micro adjuster was set to 4.5. It's shooting the 25.4 grain FX pellets at 923 FPS. It seems they all come from the factory set to 16!
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Theres absolutely nothing wrong with them being set ay 16
 
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I would think before boxing the guns for worldwide shipping - the manufacturer assembles them and not even airing it up to a max only to a basic 50 bars maybe.
Ones arrive to distributors (at geographic locations) after a long journey, it shall be their job to air it up fully and leak test overnight.
Any tuning? I would wild guess that would be an extra charge to a customer.... turning knobs or allenkey's to a written down numbers I call that a ballpark only and far from tuning.
 
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carlos_hathcock said:
I’ve had good results at 960-970 FPS with the MRD’s. Reg at 110 and micro at something above 4, I don’t remember exactly. Some great groups at 50 yards (one hole & MOA) but would open up at 100, because of the wind I figured.
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Well I use the exact same tune. But i also have the same results, one hole groups at 50 yards and less good results on the longer distances. Now i’m lowering speed a little to see of this gives improvements.
 
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