FX Wildcat 25 FPS Sweet Spot

For those of you that own or have owned an FX Wildcat 25 cal, what have you found to be the “sweet spot” for pellet velocity in your gun? My specific setup is a Wildcat Compact (500mm STX barrel) shooting 25.39 grain JSB Kings and factory AMP reg. Factory reg pressure is set at 140 bar?

When I say sweet spot I’m referring to the Knee point between power and efficiency. I understand this is what most strive for when tuning their guns.

Also, is there an excepted method for making HS adjustments to find the knee point? i.e. quarter turn, shoot 1 round through chrony, then repeat? 
 
839 seems to be where I ended up my .25 Compact with kings. WC hammer springs (at least in my experience) are temperamental. I found a small range within which they did what you expected, and then the needed to lock them in somehow. I've used Vibratite and a automotive 'trim screw' to lock them in place enough to not move shot by shot. I sold my .25 the .177 is a keeper. I have also have a .22 that seems to be good as is so I haven't touched anything on it. FX really needs to provide a way to keep the tensioner nut from moving, on some.... everytime you pull the trigger. Search for those (many) posts. 



One example...

https://www.airgunnation.com/topic/wildcat-hammer-spring-adjuster-mod/
 
I just talked with FX a couple of weeks ago and it seems now 'someone' there is making a brass backup nut to hold the stock hammer spring nut in place. Of course I bought one. It has a smaller allen opening so there is no interferrnce with the stock nut.

So far, so good.

mike

I want one - how much and what number do I call?
 
Finally got around to installing the brass jam plate on my Wildcat Compact. The jam plate seems to be working good and holds the spring tensioning nut in place. 

Did some tuning this past weekend and currently shooting 25.39 JSB’s as follws:

Avg Vel - 895 fps

ES - 7 fps

SD - 2 fps

30 shots over the reg

Very happy with those numbers. Now just need to hit the range and see if groups are any good. I haven’t touched the reg yet, so assuming it’s still set at factory 140 bars.

John
 
So do the new wildcats ( if I was to buy one now) have this problem, or do they come with Ernest’s mod already ? And I take it, screwed in all the way, it’s maxed out ? And just thinking out load, if you were to put a shim in the factory nut, where the spring sets in the recess, you could increase some more ? Or that is not a good idea ? 
 
So do the new wildcats ( if I was to buy one now) have this problem, or do they come with Ernest’s mod already ? And I take it, screwed in all the way, it’s maxed out ? And just thinking out load, if you were to put a shim in the factory nut, where the spring sets in the recess, you could increase some more ? Or that is not a good idea ?

I’m not sure if FX has changed the design or includes the mod now. I bought mine in March of this year.

The Wildcat should be tuned and ready to go right out of the box for shooting 25.39 JSB’s (if you buy the WC Compact version). I had to re-tune mine because the HS nut started backing out a little after every shot (a known problem with these guns). Most Wildcat owners end up using blue loctite or similar to hold the nut in place. I ordered the brass jam nut instead to make future adjustments easier.

I don’t recommend turning the HS nut all the way. That may ruin your gun. I think mine ended up being 7 full turns CW starting from where the threads just start catching in the rear block. 

Ideally the HS tension should be adjusted for performance, efficiency and accuracy. 875-900 fps is usually a good range to start with using the 25.39 gr JSB’s. The Wildcat Compact was designed around the 25.39 JSB’s. Check out Steve’s recent review video.



https://youtu.be/TSccc3zKi2U




 
Yes, but if they come from the factory tuned to those pellets, and while shooting them the HS nut backs out it ain’t going to stay tuned for long. It just seems crazy to me that they cost so much, and it seems everybody is totally fine with having to fix “ problems” with a brand new gun. Seems every brand has some kind of known issues. Man I just don’t know if I want to jump in to this “ sport” or not. I do, but I don’t. I don’t like problems, and it’s hard for me to buy a gun knowing it has problems before I even get it. It’s like buying an expensive fly rod and having to put new guides on because they are loose, knowing ahead of time that they do, and still buying it, knowing it ain’t covered under warranty, just crazy.