• The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back click HERE.

FX Maverick Compact .25 maxing out at 50 fpe (SOLVED)

Jump to latest Follow Reply
S

sparker

Member
Jul 16, 2023
120
25
Omaha
Hey everyone, sorry if you're tired of my threads here.

I'm going on 3 weeks with my .25 Maverick Compact and after troubleshooting regulator issues I finally have the gun "working" but I notice that when I tune it, the Pellets start to slow down again over 130 bar on the second reg.

I have the hammer spring set as heavy as it will go on power wheel #7. Any more hammer spring and the gun won't cock. I start with the reg at 100 bar and test every 5 bar as I raise to 150 bar.

25 grain pellets are maxing out around 915-920 fps
34 grain JSB MkII is maxing at 850 fps

Is this behavior normal?

Edit: Updated title, the problem was the pellet probe was blocking the transfer port and the wrong hammer weight was installed. Gun was janky as hell from factory.
 
Last edited:
  • Like
Reactions: MongooseV8
Yes, what you are experiencing is normal. Your spring and hammer energy has reached it's peak and it won't trip the valve when you reach a certain reg pressure. You can get a slug power kit for about $40 that included two heavier hammers. Huma also has a stronger spring available. Fortunately, the Maverick/Wildcat has easy access to these parts to make changes. Proceed slowly. I would start by installing a heavier hammer weight.
 
  • Like
Reactions: starlingassn
Upvote 0
jps2486 said:
Yes, what you are experiencing is normal. Your spring and hammer energy has reached it's peak and it won't trip the valve when you reach a certain reg pressure. You can get a slug power kit for about $40 that included two heavier hammers. Huma also has a stronger spring available. Fortunately, the Maverick/Wildcat has easy access to these parts to make changes. Proceed slowly. I would start by installing a heavier hammer weight.
Click to expand...
I already accessed all that, it wasn't too hard, almost lost the ball bearing. I'll look into that kit, just thought 130 bar was low to max that hammer weight out. Thanks.
 
Upvote 0
i dont own a maverick and dont know the plenum size so i cant say for sure,
but i am at 870fps with 34gn put of my impact at 113-115bar.

I've always thought the maverick made the same power levels as the impact,maybe im wrong.

130bar just seems pretty high to be getting only 850 when maxed out,
because when you tune you'll inevitably drop another 15-20fps.
 
  • Like
Reactions: HogKiller
Upvote 0
Patrick from Pyramid Air figured it out in about 3 minutes. The pellet probe was too far forward and it was choking the air supply.

So to poop on FX, here is the list of issues my gun shipped with.
1. Bad pistons on both regulators
2. Insufficient washer stacks on both regulators
3. Incorrect pellet probe placement
4. Incorrect barrel placement, barrel was so far back it was almost impossible to get magazine in and out.

Now maybe I can give this thing a proper tune.
 
Upvote 0
sparker said:
I already accessed all that, it wasn't too hard, almost lost the ball bearing. I'll look into that kit, just thought 130 bar was low to max that hammer weight out. Thanks.
Click to expand...
Those pesky 3mm ball bearings are something every Maverick owner should have 100 of. They do try to escape, white grease is your friend.
 
Upvote 0
sparker said:
Patrick from Pyramid Air figured it out in about 3 minutes. The pellet probe was too far forward and it was choking the air supply.

So to poop on FX, here is the list of issues my gun shipped with.
1. Bad pistons on both regulators
2. Insufficient washer stacks on both regulators
3. Incorrect pellet probe placement
4. Incorrect barrel placement, barrel was so far back it was almost impossible to get magazine in and out.

Now maybe I can give this thing a proper tune.
Click to expand...
time out, on #4, there is a pin in the block that is suppose to prevent the barrel from going back too far. Not user replaceable as far as I can tell from my destructive testing. If the pin is there then the transfer port groove is too deep.
 
Upvote 0
HogKiller said:
time out, on #4, there is a pin in the block that is suppose to prevent the barrel from going back too far. Not user replaceable as far as I can tell from my destructive testing. If the pin is there then the transfer port groove is too deep.
Click to expand...
Patrick told me to have the magazine installed when attaching the barrel to prevent it from being too tight. When I did that, the mag goes in and out like butter now.
 
Upvote 0
sparker said:
Patrick told me to have the magazine installed when attaching the barrel to prevent it from being too tight. When I did that, the mag goes in and out like butter now.
Click to expand...
I did the same thing when I did a destructive drop test on my Maverick Compact, on the barrel, pushed that little pin back a mm or so.
 
Upvote 0
The only thing I noticed now, when cocking the gun it felt a little funny, like there is a second spring very far back in the cocking action now that wasn't there before. The hammer cocks, but there's about 1/8th of an inch of further travel back on a second spring, like over-travel. When the pellet probe was in the factory state I never felt that, likely because the probe was further forward.

Anyway, now I'm getting 890FPS at 100 bar like the good lord intended, so now I can start tuning it. Bet my groups tighten up too.
 
Upvote 0
starlingassn said:
i dont own a maverick and dont know the plenum size so i cant say for sure,
but i am at 870fps with 34gn put of my impact at 113-115bar.

I've always thought the maverick made the same power levels as the impact,maybe im wrong.

130bar just seems pretty high to be getting only 850 when maxed out,
because when you tune you'll inevitably drop another 15-20fps.
Click to expand...
I'm getting 890 out of my .25 VP with 33.95gr. SD of 1.3 123bar on #2 Dead stock hammer/Spring
 
Upvote 0
sparker said:
I see what you're talking about on the diagram, C-54. Maybe it's not super precise? Patrick knew exactly how to cure the issue, so it must be common.
Click to expand...
Oh it's precise, I'd bet on the transfer port being mis-machined. Feel on the inside on the surface with the pin, see if it's flat. If not they screwed it up, if it is then the transfer port is a smidge too deep, not a deal breaker but certainly a PIA to have to QC a expensive gun.
 
Upvote 0
sparker said:
Either way, like I said, It's common enough that they said to have the mag in the well when seating the barrel.
Click to expand...
Yeah, it's a tolerance stack, can't get away from it. Well you can but, I doubt seriously we'd want to pay for it. With modern CNC machines, when properly set up, they should be holding ± .001" .03mm or closer, if they are paying attention.
 
  • Like
Reactions: sparker
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu