Tuning FX Maverick slug power kit

That's a solid gain! Now, you can could also up that reg/hammer spring/ slug weight as well 

Are any US dealers offering these power kits yet and have them in stock?

One of the guys I shoot with, just ordered one from SPAW. I don't know if they still have some in stock or not though.

I installed a slug power kit and a huma high airflow tranfer port to my Maverick Compact in .22 a few days ago.

Velocities were OK, got the 23g Javelin slugs to 1100 fps but i felt like i was wasting a lot of air, shotcount was pretty low and accuracy was quit bad. Also my consistency over the FX Chrony was pretty bad.

I then found this thread here and decided do modify my 13g hammer from the power kit so it becomes more like a 10g hammer. (Originally i had the 7g hammer in my maverick).

So i took it on the CNC lathe and machined 2,8mm off the front end of the hammer, resulting in a shorter, and now 10,6g hammer.

Reinstalled, and it works flawless. I am at reg pressure 120 / 145, hammer adjuster screw somewhere in the middle.

Shooting 18gr JSB Exacts at 920fps, PowerWheel on lvl 3 with an extreme spread of ~15fps, great accuracy, 4 magazines out of the 300cc bottle.
Shooting 26gr JSB Knockout Slugs at 910fps, PowerWheel on lvl7 with an extreme spread of ~15fps and 2-3 magazines out of the 300cc bottle.





modified hammer:



Shooting 26gr JSB Slugs with the 13g hammer



Shooting 26gr JSB slugs with the modified hammer:



Original Hammer 7g vs. Slug Power kit hammer 13g

Nice work on that little hammer!

7g hammer is good for reg pressure up to about 110 bars 

11g hammer is good for reg pressure up to about 150 bars

13g hammer is good for reg pressure up to max or 170 bars 



In most cases medium or 11g hammer is more than enough for most people.

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I can second this on Wildcat mk3 .25 Compact. With 13g hammer at <150 bar changing the powerwheel setting does little. Heavier weight fully opens hammer regardless of hammer spring adjustment. In other words, don't expect to go back and forth slugs to pellets leaving heavier hammer installed. I had to put 11g hammer back in to tune JSB 25.4 pellets with regulator @ 150 bar. 

you can ordered from humaair.com they have it on stock...

I'm about to install my pin probe and I'm feeling a little bit stupid here ...
There's a smaller o-ring that I have no clue where it should go, on the pin I would suggest but there's no way getting the pin in with the o-ring on.
With no o-ring I would think the probe will not stay where you leave it (unless you screw it all the way in), but it's supposed to be adjustable.
There's a video from FX on youtube installing the kit where Ernest just leaves it on the table 1:05 in. There's an unanswered comment there too on the exact thing.

EDIT: To spare someone else from the confusion, the small O-ring is a spare, there's already one in there.




https://youtu.be/XXeRPw9n9WI?t=65

@qball As always good info...Thanks man!!!

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Like Pieter said it's a wildcat probe, the pin probe isn't really all that needed nor sometime desired. You can simply open up the existing probe with a little dremal time. The pin probe may not seat pellets all the way and might not be able to seat short slugs straight, it's made for longer/heavier slugs with flat base only. The current tube probe will properly seat everything nice and straight by the skirt or edge of the slugs regardless of the dish or pellet cavity depth. Plus the majority of the speed gain is the TP and hammer. 



7g hammer is good for reg pressure up to about 110 bars 

11g hammer is good for reg pressure up to about 150 bars

13g hammer is good for reg pressure up to max or 170 bars 



In most cases medium or 11g hammer is more than enough for most people.

Click to expand...

Interesting and correct as per FX, except in .22 cal, factory hammer weight weighed from two Sniper editions both weighed 6.079g and 6.075g respectively, a second jewelers scale also measured them at 6.0xg. Hammer weight from Slug Power kit weighed 13.04g, so that is spot on.

I bought a second slug power kit and on my lathe worked the second 13g one down to 11.08g, now I have all 3 weights, definitely find the 11g is best in .22 cal unless probably if you want to run insane reg pressures you will need 13g one.

Follow up to a thread from last year. Today I found slug power kits for my 0.22 maverick at Pyramyd Air.

https://www.pyramydair.com/product/fx-wildcat-mkiii-maverick-slug-power-kit?a=9842States only available for "Adjustable pin probe for .22 caliber, with .25 caliber sleeve"

I just ordered one. Not planning to switch my liner which is FX Smooth Twist X Superior Liner but not sure of the twist rate from the one provided to me with the rifle last June.

I will remind folks that there is the video linked above shows that the installation seems reasonable by a consumer and I plan to do this myself. 

Does anyone have information on what pellet weight these kits make a difference and a good starting point to set the regulator or hammer spring. Planning to shoot velocities of 980 - 1025 ft / sec. Seem reasonable?

Thanks

I will add information from a direct email conversation I'm having with another Airgun Nation User. 

Yes I installed the slug power kit myself. Was not difficult. Followed the you tube videos

1. https://www.airgunnation.com/topic/fx-maverick-slug-power-kit/?referrer=1&nbsp; (AIrbuks)
2. https://www.youtube.com/watch?v=XXeRPw9n9WI&t=475s (Ernest Rowe)
   [/LIST=1]
   
   Basically three steps:
   
   1. Replace the probe
   2. Replace the hammer wheel
   3. Rotate Barrel to use the slug transfer port (Larger double air hole
      [/LIST=1]
      
      PLEASE NOTE THAT THE POWER KIT FOR THE MAVERICK IS DIFFERENT FROM THE KIT FOR THE IMPACT. 
      
      I am still waiting for my FX heavy liner and carbon fiber sleeve for the 700 mm sniper barrel. I recommend the sniper for the larger bottle (you have a large power plenum to keep filled) and the longer 700 mm barrel allows more time to push the heavier slugs down the barrel to gain velocity. 
      
      I will post the ballistics chart to the forum already created for the Maverick Slug Power Kit
      
      1. https://www.airgunnation.com/topic/fx-maverick-slug-power-kit/?referrer=1
         [/LIST=1]
         
         Please let me know if you find this helpful. 

I also thought I would share my velocity chart with various slug types and weights using an excel format that I think others may find useful. I am finding that the slugs prefer a velocity

round 950 fps for accuracy but I will post that after I get my FX Heavy liner and carbon sleeve for my 700 mm sniper barrel. 

Here is my setup with the FX Maverick, Saber Tactical rail and monopod, ATN Digital scope with range finder and the FX chronograph attached via using picatinny scope rings using a 3/4 " pvc pipe below the barrel to prevent the radar from changing barrel harmonics when I'm not using the radar (I borrowed the idea from an Airbuks video I viewed on line). This will be important when I report on my best velocities for accuracy. 

I’ll be very interested to see your accuracy results when you get the heavy liner and sleeve. 

I put a power slug kit in my .25 maverick and got 100 fps increase with 34 grain jsb's. Check huma air usa. I think that's where I bought it. 3 day delivery from the Netherlands, everytime. I don't know how they make that happen!

Hei all...., i have a maverick in 25 cal, my reg pressure are 160/130....i will install the slug kit but i dont know how much mm i must have by the hammer screw....?

I need help