FX impact 22 reg setting low

It is scraping 900fps at 100bar then getting progressively slower as I increase up to 150. I'm thinking maybe the gage is on the turps and false reading really low * I've already ordered a new one. Any one else had this happen?



I cant imagine that the stock FX Impact hammer would have issues overcoming the Impacts valve spring tension at pressure below 145Bar. Perhaps the valve spring adjuster on the Impact is not "playing well with others". Just a thought.
 
Thanks all, I should further clarify that setting it on Max was the baseline, as reducing it down to min just slows the pellet further across the board. Max measured speed has been 900FPS at around 100 Bar on max- dropping it to 5 on the wheel is resulting in 890fps. Rifle is brand new impact x fired around 250-300 pellets. Ive read about increasing pressure doesn't correlate to increased speed and the opposite can be the end result hence my question about the gauge, what sort of max speed should i be looking for with 18gr Jsb heavies? As i may just leave it where its currently at and wait for a new gauge. 
 
100bar seems low to get 900fps from an 18gr pellet. Maybe your gauge IS off/not reading accurately.

I know it's not the same gun, but my Crown 22 would no way get anywhere near that velocity at 100bar, or even 120bar. It thinks about it at 125bar though.

Right now I have my reg set at 140bar, power wheel on 25/30cal, hammer spring adjuster on 5 with maximum compression.

I get 927fps average with the JSB 18gr. 500mm barrel.

1547335591_18598146415c3a77a7ea5571.92498766_Screenshot_20181224-204928.png

 
tightened it up to 18.5mm - 100 bar is now producing 930fps on max

- about 110 bar (ish) saw it at 980fps. 

now im confused as i though it would have dropped the FPS as it allows less air through with a tighter hammer spring..? and I would need to crank up more reg pressure to bring it back up. 

other things to note is the fps is sometimes appears to be varying around on the same setting ( varying around 20fps) 

then on other power settings its really uniform. 

Should I be paying off the manometer reading and waiting for a new one ? or fine tuning the hammer spring . im not chasing max speed just best accuracy. 

using the generally accepted speed of around 900fps as a start point.

Thanks so far to everyone pitching in on this - its been a learning / scratching the head experience






 
Glad you're getting to the bottom of your problem..hammer spring / energy was part of the issue. 930 fps @ 100 bar is quite high...gauge is likely off? 100bar = 1450 psi, if I do the math that I do so well, I get 864 FPS as your peak...provided 500 mm barrel that most .22 cal have...to get 930 fps I need to put pressure up to 115 bar. Now if you have a 600 mm barrel then...I get 100 bar making roughly 930 fps and your gauge is fine...so that information should help pertaining to gauge accuracy...at least IMO



GL
 
Math is one thing, actual results are another.

Good luck getting an 18gr 22 caliber pellet going 930fps out of a 500mm barrel at 115bar.

I have...you wanna know more details or just assume? Tell me more about how I am wrong...this is 90% bore porting, proper plenum size, 1650 psi and 19.5 barrel...and yes its been done and will be again, and again, and...



What happens if I take away the proper plenum from the above? Tried, tested, and mathematically modeled, 913 fps @ 18 cc plenum, @ 891 fps for 15 cc's plenum, 831 fps fro 10 cc plenum, oh wow look at all those fps just go right away with smaller plenums..
 
You admittedly have zero hands-on experience with FX airguns. Yet you insist that the calculations you make, based upon generic parameters, apply to this FX model the same as they apply to whatever brand you have experience with, or for all models across the board.

The advice I gave was based upon my actual results with a similar rifle, which is far more accurate than the calculations you insist are correct in thread after thread dealing with rifles you have no experience with.




 
So I've been playing with the hammer spring tension- so far ive worked out it is increasing the speed of the pellet when set at 100bar ( .22 18gr is now pulling around 910fps / 100bar /18mm HST - 600mm x barrel 

What i appear to be noticing is the speeds seem to be a bit more uniform when more tension is being applied on the hammer. ive still got a fair bit of gap there (3mm or so ) before it maxes out. I haven't had time to start increasing pressure here but it would seem from the last run it will significantly increase. 

Im not chasing speed but accuracy so i guess all i can do is keep playing , however does anyone have any scoop on winding out the HST to max? ( Earnest does it in 1 video) Pros/Cons