Tuning Your M3 Tunes Here

MKII .177cal, 500mm stock barrel, sock pin probe

Reg- 80, micro- .769, wheel-Max, valve- .298"

13.43gr pellet

793, 797, 803, 800, 812, 799 average 803 FPS...(19.47 FPE Hunter Class)

10.3gr pellet

Average 882 FPS

8.4gr pellet

Average 930FPS

The 13.43gr group, at 25 yards, was the tighest, holes were touching or pellet-in-pellet. Other two weights opened just a little. Looking at FT possibilities with a 13.43gr pellet.

Thanks very much! Really appreciate it

M3 .30 Cal. 600mm STX. Carbon fiber sleeve. DonnyFl Ronin. Stock pin probe.

Reg 1 = 175

Reg 2 = 135

Macro = 16

Micro = 4.5

Valve = .441"

FX integrated harmonic tuner set at 6

44.75gr Hades

Avg 929 fps

1/2" or better grouping at 50 yards

I also shot some Hybrids through the same setup and they grouped 1/2" but hit slightly down and right by 3/4 of inch.

Looks like I found my tune today. 35 yards no wind.

FX Impact M3, .25 caliber, 600mm, DonnyFL Sumo, CF Sleeve
FX 34 grain pellets

1st Reg: 150
2nd Reg: 120
Macro: 14
Micro: 3.75
Valve: 4 or 10.59mm
Avg Velocity: 887.2 fps


Measured 0.3975 inches for a center to center group size of 0.1475 inches. I'll take it!

This is Anubis, a impact M3 in .25 cal shooting nsa 29.5 grain slugs with a superior heavy liner, cf sleeve and a slug power kit installed. I currently have 1st Reg At 175 bar 2nd reg at 150 macro is 16 micro is 4 1/4 valve is almost 5lines (11.80mm) and can not get more than 930fps my deviation is between 20-25 with nsa 29.5 grain slugs but it is grouping lovely. My question is could it be my location I’m in Orange County NY my outside temps are between 6 and 35 degrees when I do get out to shoot, yes this is my first impact I have a gen 1 bobcat in .30cal 

Do yourself a favour and get rid of the slug power kit but just keep the slug probe installed, i have the M3 in .25 with a standard 700mm superior liner fitted and i have almost identical reg settings to yours along with the valve,macro,micro and i have 38g prohunter slugs pushing 980fps.

Lots of people have been fitting slug power kits to there M3s and have been getting problems , just try it as stock first before fitting the probe but make sure your barrel is turned to slug port.

Thank you will give that a try this weekend for sure 

No worries, i myself didnt fit the slug power kit but a friend who got himself a M3 in .25 just a little while after mine did fit the SPK and encountered all sorts of issues, he had the same reg pressure, macro etc as mine, but fitted the SPK and a 700mm superior heavy liner and it grouped horrendously, he took everything out and retuned his rifle and all is working great now with slugs up to 41g in a 700mm superior liner.

So I took this tune out to 100 yards today. I'm happy with this tune.

FX Impact M3, .25 caliber, 600mm, DonnyFL Sumo, CF Sleeve
FX 34 grain pellets

1st Reg: 150
2nd Reg: 120
Macro: 14
Micro: 3.75
Valve: 4 or 10.59mm
Avg Velocity: 887.2 fps

Lots of people have been fitting slug power kits to there M3s and have been getting problems , just try it as stock first before fitting the probe but make sure your barrel is turned to slug port.

Click to expand...

I' m one of those guys but it was due to my poor armourer's skills. Now I have tested the SPK extensively and I could get 39 fps more velocity or 20b less reg2 pressure for the same velocity as before. In the SPK I'm using the 2 spacers and the pin probe but neither the rubber ball and the new spring. The first spacer adfs much more speed than the second. I'm shooting .217 Patriots in 34 gr. See my post below.

https://www.airgunnation.com/topic/should-fx-recommand-not-to-install-the-slug-power-kit-on-the-impact-m3/page/2/#post-1170087

I just wished that FX gave the right info out straight away, my friend would of saved alot of cash trying to get his M3 tuned for slugs! 

I just wished that FX gave the right info out straight away, my friend would of saved alot of cash trying to get his M3 tuned for slugs!

Click to expand...

1st hypothesis: good engineers are rarely good communication managers.

2nd hypothesis: marketing manager tells everyone to shut up

Ha ha ! Im my experience its probably the second one !

Other tuning learning: I'm quite impressed by the velocity difference beween .217 and .218 slugs. Diameter is just increased by 1 thou BUT for the very same tune de velocity of .218 are 30fps less than the .217. Of course .218 generate more friction but I would't imagine such an impact on the velocity. Anyone with a similar experience?

@ redwolfPaul25 Thank you sir, took your advice and removed the SPK but kept the slug probe. Went from 930ish fps to 1020fps with an sod of 6-12fps what a difference will fine tune this weekend on paper and get back to you. Wish to thank all for the advice and will give updates on the progress

I received the rifle on 12/29/2021 and am still learning it but not new to pcp’s or air rifles just new to the impact now to get a good compressor without taking out a 2nd mortgage lol

I have the Air Venturi compressor and have been very happy with it. Fills the tanks and the guns.

No worries mate , im glad it worked for you.

I just bought an M3 .22 700mm used on the classified (great transaction!!!!). Its got a lot of goodies on it like the heavy slug liner with carbon sleeve, full harmonic tuning system, angled manometer bracket, all Sekhmet gauges, slug power kit installed, bag rider etc etc etc.

It’s been tuned by SPAW and tweaked a little by the original owner to shoot 31.2 slugs at 1000 fps (haven’t had time to shoot and check that, but seems like its not that far fetched).

I would like to find the minimum tune as well as the max…I can play with all the tune in between, but I would like the shot count and sound level that a minimum tune can provide for the backyard plinking I do 80 to 90 percent of the time. I don’t want to change anything physical like pulling the slug kit or probe (or whatever) every time I switch to full gorilla level power to go out and shoot slugs. 

So, wondering if anyone has a tune that still keeps the slug kit etc but shoots at the minimum fps while still keeping accuracy with pellets. I have a big shelf full of JSB and Fx pellets and now slugs, so I can hopefully match a tune for a particular pellet pretty easily… just looking for someone to help me out that has done the work already if possible. I of course will have to work with the harmonic tuner and all that, but just what the regs are set to and macro micro stuff. 

Hope that makes sense. Thanks in advance for anyone that takes the time to post their tune. If I don’t hear from anyone, I will do the work and post it for the next guys. 

Cheers. 

Sharing my tune. Didn't really want to use others provided. Just switched from a. 35 to a 25 cal in 700mm. Put in the superior heavy liner as well.. Mine came with slug power kit as it was a 35..



38.5 grain Nsa 

Big wheel 8

Little dial 4.5

Valve at 4.5 lines

Front reg 162

Back reg 142

Speeds 975-980 fps



Satisfied with that