Fx Impact performance.

OK, checked speeds with regulator set at what looks like 140-145 bar. Power Wheel at MAX and valve on 4. 

Hi: 857 fps
Low: 829 fps
Ave: 842
ES: 28
SD: 7

Still not great, but the Heavies MK I grouped great. 
At 30 yes (where I zero) two 5-shot groups measured 3/8" and 1/4" respectively. I shot a couple of groups at 50 and both groups were 3/4". I have less than 100 shots through the rifle and am sure things will get better after break in. I think that the regulator will break in and ES will get better. But I'm happy with the accuracy. Not as fast as hoped for but you adjust velocity to maximize accuracy so I might be there. 
 
So my question is what is the top speed people are getting with their Impacts for JSB Heavies (34gn) at max? GQ is getting 890 others including myself are hoovering around 857-865. If I knew the average top speed I could edge my regulator to that point and still be OK......I think.

One thing I discovered the other day that my speed was dropping. So after checking the regulator, check and valve, check...I noticed that the power wheel adjust screw had worked itself loose. I was having weird jumpy velocity readings so I reset and will use VC-3 thread locker on it to keep the setting. I'm out of town for another week so will check this on return. 
 
Drumsguns this wheel screw is a problem for everyone and you did the right thing using thread locker. Indeed this screw is part of the fine tuning to get consistent velocity.
My regulator came from factory showing 152 bars. I dont trust this pressure gauge because I know it is not accurate and it is not showing what the real pressure is.
I dont trust chrony but mine seems to be accurate when I compare my my point of impact on the target using Chair Gun app.
Keep us posted with your results but I do not suggest to play with your regulator.
Play with the power wheel adjustment and the valve adjustment in front.
Having the power wheel at full power and the valve with 4 lines visible does not mean you will get the highest velocity.
If you loose air because your power wheel and valve are too much higher you will loose velocity.
The sweet spot is not simple to get that is for sure and you cannot have the same set up from an Impact to another one.
Mine barrel is a long fixed shroud without silencer in the end. It is a Canadian specs barrel.
And to finish you know that accuracy is more important than speed.
Regards
GQ
 
Hi All;
I am using .30 with jsb44.75 grains and with the regultor setting at 150 bar. the best that ı can get with the max setting is 855fps...

I have tried to adjust the valve but its useless eve if I go to 160 bar I am not able to increase the fps more than 855 so I have rolled back to 150 bar...

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