FX Maverick - Power problem

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vincbee

vincbee

Member
Jul 7, 2022
8
2
belgium
Hi guys,

My problem : I'm only able to reach 550 fps with my Maverick .30 (7.62mm) cal 500mm
I read that some reach to 900 and more
What could be wrong...

And I'm allready sorry, cause I'm new in the hobby, so I'm that heavy guy with so many question !!
Believe me, I'll try to be as light as I can ;-))

Precisions... that could probably help...
- My regs are (from what I know) setup max : 250bottle-> 180reg1 -> 150 reg2 (Is it really the max ?)
- Position 7 and setup unscrew with hex1.5 to max (with ajust wheel stuff)
- I didn't change hammer or spring (and even I allready ordered a 14gr new hammer I don't think it is the thing wich can reach from 500 to 900fps ? Or am I wrong ?)
- I bought FX Maverick with .22 cal and I change barrel with .30 and its pellet probe (hole not big enough ?)

The 2 barrels I have :
.22 (5.5mm) cal (barrel of origin) has 2 positions (2 rectangle holes et round hole)
.30 (7.62mm) cal has only one (round hole)
1) Is it normal ? Or some holes are missing on .30?
2) I noticed that 1 of the 2 O-ring on .30 cal I get is flying in the middle of nowhere... Is it normal ?

20220725_151050.jpg


3) Could you help me on what am I doing wrong - well to reach more than 500fps with .30 cal ?
4) For you do I have to buy a Humma KIT like : High Flow V2 Dual Hole Transfer Port for maverick or it is not necessary ?
5) What could be the difference from your experience if I change spring and put 14gr hammer ?

Guys English is a foreign language for me so sorry in advance for my writing mistakes :)
And thanks also in advance for your help !
 
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The .30 cal has only one round hole. Normal. You don't need a dual transfer port. I would leave everything stock for now.
Did you set the regs or did they come that way? They are fine as set for the .30 caliber.
The one ring that is loose in the groove, is normal also. I had the same question, and called FX. The one o ring has more play in the groove.
There are a few places to look. Is the breech seal there and OK? Has your pellet probe slipped so all the air power is not getting to the pellet? If those are OK, it's likely the hammer spring setting.
Again, I'd like to stress, I would NOT change anything on the gun until I got the low power issue figured out with the gun stock. You do not need to go chasing rainbows. The gun from the factory is capable of much more than 500 fps.
 
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cmatera said:
The .30 cal has only one round hole. Normal. You don't need a dual transfer port. I would leave everything stock for now.
Did you set the regs or did they come that way? They are fine as set for the .30 caliber.
The one ring that is loose in the groove, is normal also. I had the same question, and called FX. The one o ring has more play in the groove.
There are a few places to look. Is the breech seal there and OK? Has your pellet probe slipped so all the air power is not getting to the pellet? If those are OK, it's likely the hammer spring setting.
Again, I'd like to stress, I would NOT change anything on the gun until I got the low power issue figured out with the gun stock. You do not need to go chasing rainbows. The gun from the factory is capable of much more than 500 fps.
Click to expand...
Thank you @cmatera for the information concerning the number of holes, as well as the o-ring, it is reassuring.
About the pellet probe I know that it has to be fixed as close as possible of the barrel, so I'm almost sure it is ok.
But I think you touch something with the breech seal. I'm not sure of what it is... Does someone has a photo of that ?
 
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estarkey7 said:
I get 930 fps with hybrid slugs, so here are my settings.
  1. Your first regulator is too high! Tune to 155 bar
  2. Tune your second regulator to 125 bar.
  3. Install the hammer weight from the slug power kit.
View attachment 279502


Your hammer is too light to open the valve with the current reg settings you have.
Click to expand...
ok thank you, good to know about reg...
gonna put same pressure on regs

and apparently, my hammer is 10.6grams... wich is not the 7g I normally should find in the .22cal...

weird, but better for me finally !
20220730_184805.jpg
 
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vincbee said:
guys,

disassembling to check your suggestions I found an o-ring that came out !!
and I found exactly where you see my finger. Just by removing pellet probe.

Does anyone know where it's going?
Could it be the breech seal ??
View attachment 279524
Click to expand...
Likely the breech seal. Definitely needs to be replaced.
For .30cal, breech seal is 7.5x1.5 NBR 70
The outer seal (around brass inlet) is 10x2 NBR 70, so you should be able to distinguish the size differences easily.

For .30 caliber, the factory rifle comes with the 13 gr hammer weight and a 52mm hammer spring.
For .22 caliber, the factory rifle comes with the weight you showed (the new .22cal weight) and a 56 mm spring.

So when converting over, if you just get the weight, you will likely struggle to lower the hammer tension enough to have a proper velocity variation on a lower (44.8gr pellet) tune.
I would recommend also picking up the 52mm hammer spring if you have not already placed your order with FX USA. It is the same hammer spring as the Impact Power Plenum, part 2604 according to FX Impact M3 schematic (C56 https://fxairguns.com/wp-content/uploads/2021/04/F10370-Impact-M3-1.pdf)

The regulator pressures suggested (155/125) are right on the money, and your hammer spring tension adjustment will be determined on your weight/spring combination.
As a suggestion/start point:
13gr weight and 56mm spring - tension screw bottomed out
13gr weight and 52mm spring - tension screw about 3.5mm turned out (If you do not have calipers, the screw uses M3x0.5 threads, which means every full rotation is 0.5mm. This means 3mm would be ~ 6 full turns from bottom.)

If you need to increase the speed, the regulator pressures will need to be increased. Keep them within 35-25 bar apart (30 bar apart sweet spot). The max adjustment of the hammer spring tension screw is about 6.4mm, but it is recommended to stop around 6.0mm for better velocity control.

Hope this helps!
 
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910AGTR_Buck said:
Probablement le joint de culasse. Il faut absolument le remplacer.
Pour .30cal, le joint de culasse est de 7.5x1.5 NBR 70
Le joint extérieur (autour de l'entrée en laiton) est de 10x2 NBR 70, vous devriez donc pouvoir distinguer facilement les différences de taille.

Pour le calibre .30, la carabine d'usine est livrée avec le poids du marteau de 13 gr et un ressort de marteau de 52 mm.
Pour le calibre .22, le fusil d'usine est livré avec le poids que vous avez montré (le nouveau poids .22cal) et un ressort de 56 mm.

Ainsi, lors de la conversion, si vous n'obtenez que le poids, vous aurez probablement du mal à abaisser suffisamment la tension du marteau pour avoir une variation de vitesse appropriée sur un réglage inférieur (pastille de 44,8 g).
Je recommanderais également de récupérer le ressort de marteau de 52 mm si vous n'avez pas déjà passé votre commande auprès de FX USA. C'est le même ressort de marteau que l'Impact Power Plenum, partie 2604 selon le schéma FX Impact M3 (C56 https://fxairguns.com/wp-content/uploads/2021/04/F10370-Impact-M3-1.pdf )

Les pressions de régulateur suggérées (155/125) sont justes et le réglage de la tension du ressort de votre marteau sera déterminé en fonction de votre combinaison poids/ressort.
Comme suggestion/point de départ :
Poids 13gr et ressort 56mm - vis de tension à fond
Poids de 13 g et ressort de 52 mm - vis de tension d'environ 3,5 mm (si vous n'avez pas d'étriers, la vis utilise des filetages M3x0,5, ce qui signifie que chaque rotation complète est de 0,5 mm. Cela signifie que 3 mm correspondraient à environ 6 tours complets à partir du bas. )

Si vous devez augmenter la vitesse, les pressions du régulateur devront être augmentées. Gardez-les à moins de 35-25 bars l'un de l'autre (30 bars à part sweet spot). Le réglage maximum de la vis de tension du ressort du marteau est d'environ 6,4 mm, mais il est recommandé de s'arrêter à environ 6,0 mm pour un meilleur contrôle de la vitesse.

J'espère que cela t'aides!
Click to expand...
Oh yes it helps me a lot!!
And thank you for all these super clear details !
I even thought the O-ring was coming from here...
20220730_211513.jpg

Regarding the breech seal I finally understand what it is !!
And mine is of course like you said the 7.5x1.5 NBR 70 size in my .30cal barrel.

20220730_231422.jpg
20220730_231403.jpg


BUT...
I still become crazy...
The breach seal IS in place and SEEM perfekt...
The O-ring I founded in the middle of nowhere (just over the pellet probe, over my finger like in my previous photo) is exactly the same o-ring than breech seal !!!

So I've 2 breech seal !!
In good shape...
20220730_230825.jpg

Really don't know from where the second one came...

Could it be than there's 2 breech seal in the barrel ?
Perhaps here ?
20220730_231117.jpg


For the rest :
I put 1st reg at 155 and last at 125 like previous advice.

Now to have disassembled and reassembled, on my last test (position 7) I'm about 625fps !!
Guys, I won about 100 fps !!!
3 days like that and I'll be around 900 lolll
Again...
thanks all
 
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vincbee said:
Hi guys,

My problem : I'm only able to reach 550 fps with my Maverick .30 (7.62mm) cal 500mm
I read that some reach to 900 and more
What could be wrong...

And I'm allready sorry, cause I'm new in the hobby, so I'm that heavy guy with so many question !!
Believe me, I'll try to be as light as I can ;-))

Precisions... that could probably help...
- My regs are (from what I know) setup max : 250bottle-> 180reg1 -> 150 reg2 (Is it really the max ?)
- Position 7 and setup unscrew with hex1.5 to max (with ajust wheel stuff)
- I didn't change hammer or spring (and even I allready ordered a 14gr new hammer I don't think it is the thing wich can reach from 500 to 900fps ? Or am I wrong ?)
- I bought FX Maverick with .22 cal and I change barrel with .30 and its pellet probe (hole not big enough ?)

The 2 barrels I have :
.22 (5.5mm) cal (barrel of origin) has 2 positions (2 rectangle holes et round hole)
.30 (7.62mm) cal has only one (round hole)
1) Is it normal ? Or some holes are missing on .30?
2) I noticed that 1 of the 2 O-ring on .30 cal I get is flying in the middle of nowhere... Is it normal ?

View attachment 279485

3) Could you help me on what am I doing wrong - well to reach more than 500fps with .30 cal ?
4) For you do I have to buy a Humma KIT like : High Flow V2 Dual Hole Transfer Port for maverick or it is not necessary ?
5) What could be the difference from your experience if I change spring and put 14gr hammer ?

Guys English is a foreign language for me so sorry in advance for my writing mistakes :)
And thanks also in advance for your help !
Click to expand...
front reg at 155 bar rear at 125-135 pin -adjust 3.5 mm should shoot 880 on power 7 with 500mm barrel 44.75 gr jsb
 
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vincbee said:
ok thank you, good to know about reg...
gonna put same pressure on regs

and apparently, my hammer is 10.6grams... wich is not the 7g I normally should find in the .22cal...

weird, but better for me finally !
View attachment 279523
Click to expand...
Definitely the wrong hammer for the .30 cal. Your scale might be off or not sensitive enough. But the hammer you show is the 22 cal hammer. You need a heavier hammer.
 
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Ok guys, thanks to all.

My actual transfer port is impossible to remove (without flames and perhaps killing it and o-ring I don't actually have)
So I wait order with new transfer port and its new o-ring before taking any risk...

I also admit that my gauge not precise that a new one will help massively !

And I put the video that help me so much :

I'll be back :)
 
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When I got my Maverick .30 it also shot low FPS. I discovered that the hammer spring adjusting screw needed to be adjusted out to 6mm height as Ernest Rowe explained in his high power tuning video. Hammer is heavier in the .30 and your .22 hammer needs to be changed to the same one or heavier as the .30 cal. Stock port is sufficient to reach 900+ FPS with pellets. Leaks from O-rings would be the only other cause is regs are working normally.
 
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