why 140 bar

hvack

Member
May 11, 2015
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I've read that the default reg pressure is 140 bar on the fx impact .25 . I have tried 115 -150 and they all can be adjusted to shoot about the same with heavy kings . Would it be better to have 125 bar shooting kings at 830 fps or would it matter if it was at 140 bar shooting at 830 ? ( 830 is were the gun seems to like king heavy .25 ) These pressures group the same at the needed speed it seems . I have seen a video from Matt d saying that the correct reg pressure can tighten up the group and keep the pellet from spiraling . IDK what is your guys experiences ?
 
there will be a difference in shotcount per fill/efficiency too, probably you can keep the speed high with lower reg pressure but it will use larger volume of lower pressure regulated air.
results are similar, in the end you still have to go and refill the gun from a tank which has finite volume and pressure, but it will happen at different pressure.
i hope you get what i mean
 
Hey, not the same rifle (SPA M10) but i can run my huma reg. on 50 bar only and its still shooting with 20fpe using .22" JSB RS 13grain
im still testing various transferport dimensions and hammersprings to archieve the best accuracy.
i expected things like that because the rifle was shooting with 35fpe from factory. (heavy hammerstriker, strong spring, big transferport dimension)

but if you changing the reg settings you should play around with the hammerspring at least. my next step is to drill holes in the hammerstriker because it needs to be lighter for a 12fpe limit. it will not move much with a lighter spring only.

my experiences should be just a example of what could be possible to do because if you just changing one parameter... its not perfect matched anymore maybe.
 
"sirk"there will be a difference in shotcount per fill/efficiency too, probably you can keep the speed high with lower reg pressure but it will use larger volume of lower pressure regulated air.
results are similar, in the end you still have to go and refill the gun from a tank which has finite volume and pressure, but it will happen at different pressure.
i hope you get what i mean
This makes a lot of since ! How would you be able to tell when you've went to far to the other side ? ( to much reg pressure ? )
 
Hvack have you seen Teds video on tuning the Impact/Crown? Before you start check all relevant measurements with the Impact trouble shooting guide. 
Short version:
1 Start with reg pressure low so you have range above to adjust. So maybe 120 bar. 
2 Max on hammer spring adjuster 
3 Slowly ajust reg pressure up until you are around 30 fps above your intended speed. So 860 for you. 
4 Ajust hammer spring back to 5 maybe 4 to achieve 830fps. 
https://youtu.be/xxi3Vj0lkVI
I think 140bar is just a guide and it’s not tuned to a specific pellet. 
 
"sirk"there will be a difference in shotcount per fill/efficiency too, probably you can keep the speed high with lower reg pressure but it will use larger volume of lower pressure regulated air.
results are similar, in the end you still have to go and refill the gun from a tank which has finite volume and pressure, but it will happen at different pressure.
i hope you get what i mean
I agree with you .
higher pressure will save air ,But need a bit more stronger hummer spring which will cause a bit more vibration .
 
"AirSupply"Hvack have you seen Teds video on tuning the Impact/Crown? Before you start check all relevant measurements with the Impact trouble shooting guide. 
Short version:
1 Start with reg pressure low so you have range above to adjust. So maybe 120 bar. 
2 Max on hammer spring adjuster 
3 Slowly ajust reg pressure up until you are around 30 fps above your intended speed. So 860 for you. 
4 Ajust hammer spring back to 5 maybe 4 to achieve 830fps. 
https://youtu.be/xxi3Vj0lkVI
I think 140bar is just a guide and it’s not tuned to a specific pellet. 
Yes I've seen this video and have tried just this . I started at 115 bar and have been able to to achieve 860 on max hammer and then went down to wheel 5 on 115 bar to get 830 fps. It eats more air . if I turn the reg up it eats less air but the tune is not for max . max starts getting way above 860 on max wheel then I have to turn the hammer down to low. What I have found is that you can't tune for max and only be 30 fps above target fps. I have the reg pressure up now to about 133-139 and get 60+ shots power wheel on A but have to turn the valve limiter in a Lot to 1 1\2 mark . Its shooting ok but I can't tune the way the video says it just don't play out that way.