wildcat delma

I have been shooting my 22 wildcat a lot. What a great gun. It is the most accurate gun i have ever owned. Stacks pellets at 50 yards and at 75yard shoots a tighter group then my Boss if there is no wind. Ran it over the crony yesterday and its shooting the 15.89 JSB at average 920, The 18 grain at 775 average. Seems a little low to me and been thinking about turning it up so the 18 grain shoot in the low 900's and the 15's would be mid 900's. Thing is I'm afraid of screwing it up. I have never adjusted power on a PCP before. What are the chances if I adjust the power up of not being able to get back to where I started. And do you think the increase of 25-30 FPS is worth the feel good? 
 
Absolutely not I would leave it alone if it's shooting that good already. That is completely normal speed your currently getting now. I have a wildcat.25 and I'm getting 890,s with JSB.25g,s and low 800,s with the JSB 34g. I never mess with the factory reg setting if I can get great accuracy and able take down small to medium game. But in the end it's your gun and if you want to tweak or tune something then go for it. I personally don't like to mess with the regulator unless I'm having serious velocity issues but usually I like the factory reg setting. Ok I'm noticing you said the JSB 18g,s are shooting in the 775 range that is a tad slow my apologies I miss read your velocities. In that case I would tweak the hammer spring first and then if I'm unhappy with the results I would turn up the reg but only slightly. Good luck.
 
"Mr.Gadgets"Kit,
I would first take a black Magic Marker and mark the brass hammer tension screw on the back of the gun, thereby, making a reference point. If you don't like your results, you can then set it back exactly where it was.


What is the fastest fps you can get with the .22 Wildcat with 18 jsb by adjusting the hammer spring only? At what point do you have to adjust the regulator also? 
 
If your reg is set at 140 bar you should be able to get the 18's into the 900's no problem. Look at the tension screw and see how far it is turned in, my guess is it is all the way out. Seems odd though that 2 grains drops the fps that much, With the 16 you are in the 30 fpe range with the 18 you are 24fpe. Speeds should only be dropping about 40 fps with the heavier pellet.
 
If you are stacking pellets why mess with it? Sometimes people always want to make their gun shoot faster for some reason, unless you absolutely need the extra few FPS then why mess with a gun that is shooting perfectly. My father, who by the way was a lot wiser than I am, always told me, if it is working perfectly don't mess with it! As a younger man I always wanted to take things apart to try and make sure they were perfect, and got told this so many times, seemed like the times I ignored him something bad always happened! If it shoots the lighter pellets at the velocity you like and it stacks pellets then stick with those pellets, why do you need heavier pellets? Unless you need it for hunting and the extra weight and velocity is needed for a clean kill then I would leave the gun alone, just my personal view based on what a very wise old man told me, Neil.