Tuning Fx impact 177 500mm

Shooting JSB redesign @ 880 fps
20211112_190514.1636762436.jpg
20211112_190624.1636762235.jpg
20211112_190605.1636762278.jpg
20211112_190543.1636762360.jpg
lights out 50 yard ofcourse I have the 600mm
 
I have a .177 M3 w/ 600mm barrel. I asked SPAW weapons (Ken Hicks) to set it up for 12 FPE and 20 FPE using JSB/Air Arms/FX 10.34 pellets and he provided the following. This was my starting points and I can vary between these two setting for 8.4 FX/JSB, to the 10.34, to Crosman Premier Heavy (10.5g). For Howler and JSB Knock out 13 grains I open up the valve much more. If you want more info for some of my more refined settings send me a PM. Settings may not work the same for you since I have the 600mm barrel. I also asked Ken to set things up for maximum stealth since i shoot in a suburban neighborhood. Not sure if that influenced the settings he used.



Good luck!!

12 FPE ~750 FPS

Reg 1 110 Bar

Reg 2 80 Bar

Macro 1

Micro 1.5

Valve 8.2 mm (base to bottom of valve knob)



20 FPE ~904 FPS

Reg 1 110 Bar

Reg 2 80 Bar

Macro 16

Micro 3

Valve 8.6mm








 
My 500mm Mk2 is doing well with a baseline 20 fpe tune similar to 5 Thumbs above. Very flexible...wheel is at 5 for the 13.4 handling backyard pest control; H&N hunter extremes do well at 3; dial it down to min for the fx 8.4 or misc flat heads for the 10m range.

Came with the air stripper that makes it look like a 600. Added a carbon fiber sleeve, Huma dual stage tuning regulator. Waiting on the barrel tuner attachment.

Photos not loading...
 
I'm trying to get it to shoot the 10.34 jsb pellets. My impact is usually in 25 and I can get the ES and SD to single digits in that caliber. However in 177 it almost seems impossible with the power plenum. Probably to much air for that caliber.
1f923.svg
gonna have to find and early MK2 without the power plenum.




no need! Just get to the power knee at around 950-1000fps and then crank down the valve to 2 lines then you should be good. BUT given the pellets are so light every tiny bit anything off will throw off the ES. Try 12.5 NSA slugs, it's awesome. 
 
I was hoping for good results on power level 1 and then use whatever works on a higher power setting.





it depends on your definition of good results, I consider under 20 for ES and under 10 for SD good for such lightweight pellets without sorting. You might have to reset your expectation.....LOL! 

Pretty sure to get really good results you need to chock down the valve quite a bit but that kills your higher HS setting power. 
 
I'm trying to get it to shoot the 10.34 jsb pellets. My impact is usually in 25 and I can get the ES and SD to single digits in that caliber. However in 177 it almost seems impossible with the power plenum. Probably to much air for that caliber. 🤣 gonna have to find and early MK2 without the power plenum.

I just set up my .177 barrel and I have had no problems with the new larger 720 power plenum at all.. You must just not be setting it up correctly especially if you are switching from another caliber. Do you have a single reg or the dual reg on the newer M3?