Tuning FT tune -FX Impact MK II. 20 FPE

[XMX]

I want to try to use the MK II for FT match. 20FPE

Here's what I have the gun tuned at.

First time tuning the MK II. Looking for critique and suggestions. 

Thanks

FX MK II .22

JSB. 13.43

786.38 avg FPS

ST DEV. 9.3

18.38 avg FPE

40 BAR ON REG.

B ON POWER WHEEL

VALVE ADJUSTER 2 LINES .347

Accuracy is a little spotty. Goes from 1 hole groups to some flyers. Zeroed a 38 yards, have shot a 50 yds.

BTW, previous to this tune I could here the PP-the most recent large one- hiss when filling. I don't here it hiss now.

Thanks

 

[Long_Gun_Dallas]

I would try and tune this at 125 bar or maybe a bit higher. At 40 bar you are going to have valve over-travel and dwell which is really undesirable for a nice tune. Ideally this gun would have a smaller valve and plenum. You'll have to really dial the hammer back to get down to 20fpe

My idea is that at higher pressure it will be harder for the hammer to crack the valve open making it easier to dial back the hammer strength. While also giving a quick and snappy valve operation. Which should lend positively to harmonics and consistency. 

 

[qball]

40 bars is way way too low and creates a lot of turbulence at the muzzle. You can go to 90 bars and find the knee at the power curve. Then turn down the valve to the desired speed. This why you have an impact. 



if the valve/reg is too out of balance then you will lose a little consistency or bigger ES/SD. Higher reg is the only way to get all other guns besides the impact, Daystate electronic guns and Leshi to shoot lower power if it’s designed for high power with good consistency.

 

[biohazardman]

I doubt very much that FX would even recommend such a low reg pressure for the Impact. A good way to damage your gun it is. Some good advice has already been given and I would agree. 

I have my Impact, now in .22, shooting at under 20fpe with the reg set at about 120bar. It shoots the 13.43s very well at fifty yards although it likes the 18.13 a bit better and will do mostly one hole groups at that yardage.

These are the five shot groups I shot at 50 yards once I got the pellets sorted. I mixed two different pellets in the same tin while I was tuning. As you can see it did not werq out to well for me until I figured out what I had done.

 

[XMX]

Just what I needed. I was concerned with the low reg pressure. I will raise reg pressure, then try to balance wheel and valve adjuster to get the 20 FT. LBS.

Thanks for the help and your expertise. 

Bob

 

[XMX]

Your info helped out.

I have the reg at 120 and adjusted the rest to hit my numbers.

Thanks guys for helping out. I research and try on my own first but it's really a huge asset that you guys provide. BTW, what do you think this will do to my shot count? 480 bottle on gun.

I remember shooting the bell curve info on my Daystate Harrier w / Tasco Custom shop 8x40 on top, 20+ years ago. Things have come a long way.

Thank you,

Bob

 

[Corvid_hunter]

For whatever it's worth, 80bar is the MIN for the FX regulator from what I remember reading.