FX Maverick Tuning...SORT OF

[HogKiller]

Ok I admit I love messing with things that work fine. I've done a wee bit of research on tuning the Maverick, never could find the starting point for the hammer spring adjuster. Using JSB Match Diabolo Exact King .25 Cal, 25.39 Grains, So I made up something to start, on my VP .25 600mm barrel, tried 6mm, got that from Moose, who got it from FX??, used Steve's, suggestion for the front regulator of 120#. Set the rear to 78# and omg it was of the charts HOT, adjusted the HSR down and down and down, to a measured 4.28mm, final speed was 937 and a SD of 2.8 and TIGHT groups at 25 yards, like single hole tight, maybe I should use a rest next time?
HSA 4.28mm
120# Front
78#. Rear


Ok, time to rinse and repeat with my Maverick Sniper, I was going to use it for heavier pellets but....had a close to major disaster as in OMG did I FU the gun type. Got two slugs jammed, pulled the barrel got the jam cleared, got the mag out and....went to cock it...oh oh NOTHING. Ok hitting head on table isn't working so, let's try degassing it and hope. WHEW that did the trick. So....
135# Front Reg.
100# Rear Reg.
HSA 4.5mm. #7. 937fps. 50LB#

Now, please note the LONGER barrel with higher pressure and essentially the same HSA is the same darn speed, same SD, with the same absolutely awesome results.

As a note, on the HSA, and this is important, there are 4 components to the HSA, the body, the adjusting screw, a very tiny plastic spacer and the set screw on the side. That setscrew MUST be snug. I'm almost considering using some Loctite blue on it, just so I can get a nice firm feel on the adjuster and NOT have the set screw back out.

Oh that little ball bearing you just dropped and have spent 2 hours looking for. 3mm at Amazon. Buy a bunch, like 20. I'm just covering my bets on those little suckers.

HK

 

[scottg0814]

I got this from FX Service. Factory tune for .25 Maverick

Thank you for the information here is the tune for your rifle.

Caliber	Reg 1	Reg 2	Hammer Macro	Hammer Micro	Pellet Weight	Velocity
6,35	150	120	7	19,3	34,8	900

I had to ask again cuz I didn't understand the 19.3mm for the Hammer Micro. Their reply:
This measurement is how far your 1.5mm sticks inside the power wheel on "Adjust".

Out of curiosity; When you say 4.28mm HSA, how exactly are you measuring that?

 

[dens228]

I got this from FX Service. Factory tune for .25 Maverick

Thank you for the information here is the tune for your rifle.

Caliber	Reg 1	Reg 2	Hammer Macro	Hammer Micro	Pellet Weight	Velocity
6,35	150	120	7	19,3	34,8	900

I had to ask again cuz I didn't understand the 19.3mm for the Hammer Micro. Their reply:
This measurement is how far your 1.5mm sticks inside the power wheel on "Adjust".

Out of curiosity; When you say 4.28mm HSA, how exactly are you measuring that?

Are you shooting a sniper or a VP?

 

[scottg0814]

Are you shooting a sniper or a VP?

Sniper

 

[HogKiller]

I got this from FX Service. Factory tune for .25 Maverick

Thank you for the information here is the tune for your rifle.

Caliber	Reg 1	Reg 2	Hammer Macro	Hammer Micro	Pellet Weight	Velocity
6,35	150	120	7	19,3	34,8	900

I had to ask again cuz I didn't understand the 19.3mm for the Hammer Micro. Their reply:
This measurement is how far your 1.5mm sticks inside the power wheel on "Adjust".

Out of curiosity; When you say 4.28mm HSA, how exactly are you measuring that?

Digital calipers, thank you Harbor Freight, Measure the OAL, Over All Length, set to zero, then measure the body, there is your difference, obviously you can go the other way also. I’m thinking they are measuring the OAL, I’d have to tear one of mine apart to check but it seems right.

 

[HogKiller]

Sniper

Frankly, I don’t think it matters one iota.

 

[Vetmx]

I read what you said in the other topic. What is going against common wisdom here?

 

[HogKiller]

I got this from FX Service. Factory tune for .25 Maverick

Thank you for the information here is the tune for your rifle.

Caliber	Reg 1	Reg 2	Hammer Macro	Hammer Micro	Pellet Weight	Velocity
6,35	150	120	7	19,3	34,8	900

I had to ask again cuz I didn't understand the 19.3mm for the Hammer Micro. Their reply:
This measurement is how far your 1.5mm sticks inside the power wheel on "Adjust".

Out of curiosity; When you say 4.28mm HSA, how exactly are you measuring that?

I just measured the overall length/height of the Hammer Micro as they call it, the HSA and it’s 20.57, so a bit over 1.2mm Longer. My feeling is that the OAL is easier to measure. If one really wanted to get into the weeds, you’d calculate the depth of the hole that the spring sets in, subtract that from the body measurement and add the height of the screw.

 

[HogKiller]

I read what you said in the other topic. What is going against common wisdom here?

Basically, a longer barrel = more speed and more pressure = more speed. I’ve got a 100mm longer barrel, 20# more pressure and getting exactly the same speeds. Now down in the weeds, I could check the hammer weights, the possible differences in springs for a possible explanation but….nah it works, so no. What I am going to do is mess with the Sniper and crank up the HSA to get the heavier 33.95 JSB Heavy’s to speed and hopefully the same accuracy.

 

[Vetmx]

Are you shooting slugs out of the longer barrel? If you are shooting a 26gr pellet then a 26gr slug, the slug is an automatic -40fps or more.

 

[Vetmx]

If you are shooting the same pellet out of both then the simple explanation would be that you have the Sniper set way below the plateau. What are your max speeds for each gun at their reg settings? There will be a huge difference between the guns then. You just have the Sniper turned down more.

 

[HogKiller]

If you are shooting the same pellet out of both then the simple explanation would be that you have the Sniper set way below the plateau. What are your max speeds for each gun at their reg settings? There will be a huge difference between the guns then. You just have the Sniper turned down more.

Nope, the Sniper is set higher, per my numbers, not much but still by 20#. I just found it interesting is all, both are perking along nicely and absolutely tight deviations and spot on groups. Literally the same pellets. Wouldn't be a comparison using different ammo. Now not knowing the bore size tolerances and the like might account but meh, I don't have access to all of the fancy inspection equipment any more. I wish I had it and access to my ultra fancy grinding machine and machine shop.

 

[Patrick1]

How’s your spread and avg velocity?

 

[Vetmx]

It has to be set higher because you are cracking a valve with 100b behind it compared to 78b. The numbers concerning your hammer setting are only related to a certain reg setting. Once you bump up the reg, all your previous numbers only represent what’s below your new working range which has moved up. If your 78b gun is set where it should be in the working range below max speed, let’s say -4%, then your 100b gun with your setting or numbers is set possibly 8% below max or plateau speed. Nothing unusual about what’s going on other than you have the Sniper turned down too far. But as long as you are happy with the groups and how consistent the gun is from max fill down to when you refill it, you’re good to go.

 

[HogKiller]

How’s your spread and avg velocity?

It’s in the first post. BUT soon change tomorrow when I post for the FX Maverick .25 Sniper, after a small tweak and measurements. Currently perking along at 954 with a SD of 1.5 for 4 rounds…. with BOTH JSB 33.95 and 25.39, absolutely drilling it at 25 yards, about the max for my yard. I can get out to 30, but was in a hurry to try some stuff.

 

[HogKiller]

Ok, I promised the FX Sniper numbers but, I'm not thrilled with it, something went a touch haywire, not BAD but not where I think it can be. I did put on a carbon fiber sleeve yesterday and as a note USE THIN 2 part epoxy, not JB Weld for steel.

So the final numbers on the VP 600. Got the Carbon Fiber sleeve epoxied , see note about THIN epoxy, had some moments of terror there.

Barrel set to Pellet

HSA at 20.34mm FX calls it the Macro Adjustment

Front reg 120 bar

Rear reg 78 bar

HSA dial to 5 FX term Hammer Macro

Shot count: 10
Low: 946
Hi: 958
Avg: 951
Spread: 12
STD Dev: 3.6
946
951
949
953
951
949
949
956
951
958

51 ft/lb energy

25 yards 80ish degrees, mild breeze, front rest bi-pod, rear on my shoulder.

 

[HogKiller]

Are you shooting slugs out of the longer barrel? If you are shooting a 26gr pellet then a 26gr slug, the slug is an automatic -40fps or more.

I'm shooting Heavy's and slugs, or at least that is my thought. Nothing over 35gr I've have to go with the Slug setting on the barrel to get enough air without going nuts on pressure. I'm shooting, pun intended, to get everything close enough to dial up to 7 for the slugs/heavies and 3 or 4 for the 25.39's I think it's possible to do that.

 

[2L8]

I'm shooting Heavy's and slugs, or at least that is my thought. Nothing over 35gr I've have to go with the Slug setting on the barrel to get enough air without going nuts on pressure. I'm shooting, pun intended, to get everything close enough to dial up to 7 for the slugs/heavies and 3 or 4 for the 25.39's I think it's possible to do that.

I think you have the desire to make it work for you. Share your tuning path. @Vetmx is no slouch and his wisdom is valid, make no mistake. Head and you will be rewarded.

Patrick

 

[TheCarFather]

I've got a Maverick 600mm in 25 caliber and can share my tune settings. I'm not sure exactly where the internal hammer screw is set at, but it's close to being in the middle of adjustment. My regs are 160/135 and on PW7 I'm getting 935fps with FX 34gr pellets, and Hades 26.45gr pellets at 945fps on PW5. Also shoot the FX Hybrid 26gr slugs on PW7 at 985fps. Both the 34gr FX pellets and FX Hybrid slugs group into one hole at 35 yards for me, same point of impact as well. Hades groups are a little bigger as I notice a higher velocity spread on lower power wheel settings. I get a very tight velocity average on PW7 and that number seems to go up as I move down on power wheel settings.

 

[Sideout]

I'm jumping in on this thread for advice, seems like you guys have tried a lot of different combos. I recently purchased the Maverick with 600mm barrel. Regs set at 140/110. I shoot the JSB 34 grain pellets on PW7 with those reg pressures and like the accuracy. Great groups at 45-50 yards and also have a 6"x6" target at 115 yards that is easy to hit. I also shoot JSB 25 grains on PW4 and at 45-50 yards they make a nice group. However, I cannot get the JSB 25 grains to shoot straight at the 115 yard target, they miss right. I have to adjust 4-5 MOA left of target to get them to hit at 115 yards with no wind. I have leveled the rifle and scope to make sure it's not a cant issue. Any thoughts on why this is occurring with the 25 grain pellet? Thanks.