FX Wildcat .25 - Magical FPS with 25gr JSB/AA Pellet

I've been doing some research and haven't found what I was looking for yet looking for easy way out. I know I need to do my own testing and research with my rifle. Has anyones testing found that magical velocity for a 25gr JSB/AA pellet for maximum accuracy with FX Wildcat .25? My WC rig is shooting 908fps average over 6mags before falling off reg. Shoots okay. I guess just looking for a reason to heat up the HT adjustment nut and back down or increase and everyone's thoughts with the Wildcat .25. It took me 9months to work up the courage to heat up my Royale 500 to bump up velocity for the heavies. 
 
A particular Youtube Airgunner (considered somewhat of an expert by many) has been known to mention speeds that he likes to send the JSB 25.39gr down range.....I could say go watch a bunch of videos and figure it out, or I could share....Hmmm.

OK, you twisted my arm.....It has been mentioned that the 25.39gr likes to leave the barrel at around 830fps on FX guns. 862fps has been mentioned by others, so maybe something in that range might make you smile? Have fun. (hope it helps, but remember sometimes advice is worth exactly what you paid for it?) I do hope it helps though.
 
there is no such a thing like magical fps.
however 
if you go too low the wind will push it too much around, if you go too high it will lose precision too. but it is a wide wide range

how do i know? i have got a traditionally rifled .25 which single holes all the way down to 450fps in no wind.
Plus how could it be that in countries with power restrictions airguns still do so well if the myth was true? naaah

EDIT: perhaps the magical fps myth must be a FX smooth twist speciallity! more likely there is a technical problem with a particular gun or it is not tuned right. correct me if i am wrong
 
"sirk"there is no such a thing like magical fps.
however 
if you go too low the wind will push it too much around, if you go too high it will lose precision too. but it is a wide wide range

how do i know? i have got a traditionally rifled .25 which single holes all the way down to 450fps in no wind.
Plus how could it be that in countries with power restrictions airguns still do so well if the myth was true? naaah

EDIT: perhaps the magical fps myth must be a FX smooth twist speciallity! more likely there is a technical problem with a particular gun or it is not tuned right. correct me if i am wrong
Respectfully, and as per your edit: Yes, your non-FX barrel is an invalid apples to oranges comparison. 
 
My WC also takes a couple of rounds to reach speed. Strange thing is that if I burn a couple in the morning it's good for all day. Shoot a couple in the morning to reach speed, leave it all day and that evening it will still be right on with first shot. mine is shooting right at 900 with the 25's and is just accurate out to 75 yards. Have not really tried beyond that. Shoots the 34 grain in the high 700's. Really needs to be turned up to find the sweet spot. Sylvan