FX FX Impact sniper M3 700mm .22 with heavy liner

[Aesalon]

Hi guys!

I'm new to the FX Impact M3 world, so I'm trying to find the way to get the best of my gun. I have a 700mm .22 with a superior heavy liner, the rest is stock. My objective is to shoot medium weight slugs (~25 gr) with precision as far as possible. I don't really care about sacrificing the total number of shots that I can get out of my bottle.

I'm currently pushing JSB KnokOut slug 25.39 gr .217 at about 930 FPS average. These are my tuning settings:

First reg: 155 bar
Second reg: 115 bar
Macro: 16
Micro: 4 and 3/4
Valve: 4 lines

I'm still getting quite a high standard deviation in FPS but the gun is nearly new, so it should take some time to settle.

Do you think that I should push for higher FPS for my objectives? Can I achieve that by simply increasing the pressure of both regulators?

Thank you

 

[Trucker3573]

I never really shot slugs so I’m not sure about the proper speed. I just have a cpl observations. The first is that those slugs may end up shooting fine out of your set up but I’m pretty sure the heavy liner isn’t necessary for 25 gr slugs and may not be the best choice. Again not positive. As for the velocity extreme spread I think it might be your hammer hitting the valve too hard. At 115 bar with non super heavy slugs your micro hammer setting being at 4.75 seems quite excessive. This will be easy to determine. Try backing it down a few clicks at a time shooting over the chrono each stop. You are looking a decrease in velocity. It’s possible you may actually see the speed start to go up a bit if you are over powering the valve but you want to look for a point of speed reduction. If the speed immediately starts to drop then you aren’t over powering the valve. I however suspect you probably are but who knows. Keep track of your clicks and what direction. I would write it down. If the velocity does immediately start to drop go back to the starting point and do the reverse. Slowly increase the micro a few clicks at a time and look for a velocity increase. In this direction you would stop when the velocity stops climbing. This is the general approach when tuning it.
To answer the second part you never want to make velocity adjustments based upon regulator changes alone. You always need to adjust the micro either up or down depending which way you moved the reg pressure. When adjusting the micro you are looking for that balance point where for the reg pressure you are set at the velocity stops climbing. At that point your hammer strike and reg pressure are balanced.

 

[Trucker3573]

If you want shoot me a pm. Can explain on the phone. Might be clearer.

 

[Aesalon]

I never really shot slugs so I’m not sure about the proper speed. I just have a cpl observations. The first is that those slugs may end up shooting fine out of your set up but I’m pretty sure the heavy liner isn’t necessary for 25 gr slugs and may not be the best choice. Again not positive. As for the velocity extreme spread I think it might be your hammer hitting the valve too hard. At 115 bar with non super heavy slugs your micro hammer setting being at 4.75 seems quite excessive. This will be easy to determine. Try backing it down a few clicks at a time shooting over the chrono each stop. You are looking a decrease in velocity. It’s possible you may actually see the speed start to go up a bit if you are over powering the valve but you want to look for a point of speed reduction. If the speed immediately starts to drop then you aren’t over powering the valve. I however suspect you probably are but who knows. Keep track of your clicks and what direction. I would write it down. If the velocity does immediately start to drop go back to the starting point and do the reverse. Slowly increase the micro a few clicks at a time and look for a velocity increase. In this direction you would stop when the velocity stops climbing. This is the general approach when tuning it.
To answer the second part you never want to make velocity adjustments based upon regulator changes alone. You always need to adjust the micro either up or down depending which way you moved the reg pressure. When adjusting the micro you are looking for that balance point where for the reg pressure you are set at the velocity stops climbing. At that point your hammer strike and reg pressure are balanced.

Thank you @Trucker3573 . I will try this approach.
I have also ordered a number of slugs from different brands and weights. This should also hopefully help me find the ideal slug for my configuration. I'm currently not getting terrible groups with the JSBs, but I know that it can be much better based on what I have seen published out there on different sources and this forum as well.

Here are some groups that I shot recently, also with the JSBs. The top two lines at 50 meters and the bottom line at 100 meters. The size of the black dot is 2cm approximately.

 

[Trucker3573]

If it were me I’d learn the gun with some king heavy 33.95 grain pellets. Much more forgiving and you can learn adjusting the gun without chasing accuracy. What little I have dabbled in slugs I have found they aren’t as easy to get right as YouTubers would make it seem. Have to have the right diameter for your liner. Right twist rate and it’s more than just the right speed. The right tune to produce that speed as slugs are much more sensitive to excess air coming out behind them when they leave the barrel. If you run some 33.95 at 920-930 the 50m groups will be a quarter of the size as those if you do your part.

 

[Peashooter]

Thats not as good as it can get at 100 M, even with me only having .177 / 4.5 mm experience.
In my pea caliber the Zan slugs fly better than JSB KO, but that's just me pea shooting
Also for me 10 grain JSB KO MK3, well they are A LOT better than 10 grain Zan which do not fly well in my Maverick with Heavy barrel or the Epic airguns Two i shoot at the moment.

Me shooting 93 M a few weeks ago, shooting 13 grain Zan slugs,,,,,, and i can do better than that too, some days.

I would listen to the pellet talk though, CUZ in .22 you should be able to shred 2" / 5 cm targets like i do.
I would for damn sure shoot more pellets if i was able to shoot the larger .22 / 5.5 mm caliber

My MAX range is 123 M and i have great fun shooting that far with my peas, and still keeping to the small targets.

 

[Peashooter]

Not familiar with .22 or the impact, but i think you would want a higher REG pressure, i am up around 150 BAR when i try to shoot 20 grain 4.5 mm slugs

Also it is my feeling that though i can shoot say 970 fps speed with 13 grain and only 60-70 BAR on the regulator, somehow it is more accurate if i shoot the same speed but with 90 - 100 BAR on the regulator.

I would for sure guess you need 150 BAR if not more to push a 25 grain :22 slug, that is what i would guess if someone asked at least.


PS. my Maverick cane from the factory set to 90 BAR for 4.5 mm FAC rifle ( back then 600 mm barrel )

 

[humbled.ag]

First reg 170, second reg 130, power wheel 17ish, macro 3. Valve throw likely between line 3/4. This should get you in the low teens to single digits for extreme spread. I've found slugs give better chrono numbers than pellets, even if they aren't as accurate.