FX Dreamline owners ... tuning

[Marc In Iowa]

Well, my Dreamline has arrived (177 BullPup). Now ... the tuning.

I'm tuning for 177 GTO 6.8 grain lead-free.

Guess what? I hardly know anything about tuning a Dreamline! The manual that came with my new rifle isn't even specific to the Dreamline. I had read a B.B. Pelletier post where he mentioned there is a new manual and I found it on the web in PDF.

The manual is fine but not much info about how to properly tune the Dreamline. In particular I'm finding the action of the power wheel pretty confusing. Turning it up or down gives me very inconsistent results. Maybe the regulator just hasn't settled in yet? There's no instructions in the manual for adjusting the grub screw on the hammer spring.

I have watched two YouTube videos on tuning for FX (Impact). Seems like the concepts are likely the same.





Any folks got some sage wisdom for a new Dreamline tuner?

At the moment I've got the regulator set for about 60 bar (pretty low). Perhaps too low?

I'm getting about 850 fps at this tune.

Hammer spring is just under maxed out.

Maybe I'd do better with a higher reg pressure but way less hammer spring? I'd sure like that power wheel to let me fine tune the fps.

[RDB]

No dreamline here, Joe Kool will probably catch this and help you in the right direction.

But i would bump the reg pressure. It will make it harder to crack the valve open and probably give you a better range of adjustment on the power wheel.

[JoeKool]

Well, my Dreamline has arrived (177 BullPup). Now ... the tuning.

I'm tuning for 177 GTO 6.8 grain lead-free.

Guess what? I hardly know anything about tuning a Dreamline! The manual that came with my new rifle isn't even specific to the Dreamline. I had read a B.B. Pelletier post where he mentioned there is a new manual and I found it on the web in PDF.

The manual is fine but not much info about how to properly tune the Dreamline. In particular I'm finding the action of the power wheel pretty confusing. Turning it up or down gives me very inconsistent results. Maybe the regulator just hasn't settled in yet? There's no instructions in the manual for adjusting the grub screw on the hammer spring.

I have watched two YouTube videos on tuning for FX (Impact). Seems like the concepts are likely the same.

Any folks got some sage wisdom for a new Dreamline tuner?

At the moment I've got the regulator set for about 60 bar (pretty low). Perhaps too low?

I'm getting about 850 fps at this tune.

Hammer spring is just under maxed out.

Maybe I'd do better with a higher reg pressure but way less hammer spring? I'd sure like that power wheel to let me fine tune the fps.

First, congrats on the new gun! 👍🏽

Second, it sounds to me if you’re going to be shooting those GTO 6.8 grain pellets mainly than that is exactly the speed I’d want them shooting at (850fps). 

Third, when tuning you have to ask yourself what ammo will I mostly shoot, and for what purpose?  First determine that?  What power do you want your .177 FX DreamPup? Personally I would tune the gun’s MAX power settings at it’s max power potential for heavier .177 ammo.  You could always dial it down with it’s built in external power controls.

On a side note, I’ll tell you this information.  I just acquired a FX Dreamline Classic in .177 that I had Earnest & Newman at FX USA  tinker and tune for me.  Well they set it up with a 90 bar regulator pressure shooting JSB 8.44 @ 950fps for 16.92fpe.  The Dreamline in .177 is advertised as a 18 to 20 fpe airgun.  IMO, unless you specifically want a lower power airgun I’d shoot for a 18 to 20 fpe tune for that .177.  I am a huge fan of and my favorite .177 pellets are the JSB Exact Heavy 10.34 grain.  So I have re-tuned my Classic Dreamline .177 @ 110 bar with the hammer spring tension harmonically and efficiently adjusted to yield 950fps with those JSB 10.34 grain pellets for 20.73fpe.
The accuracy is mind boggling. 

It’s all about what you want your airgun to do, but that Dreampup will do 20 foot pounds energy with ease! 

Ask away I can help you. 😎

[skorec]

For  lower power/pressure  ( 10  FTE/70bar ) you may taste also lighter JSB Exact Express too.

[Marc In Iowa]

This is the first regulated air gun I've ever tried to tune.

My current theory is ...

I've got the reg set so low (60 bar) that the hammer barely has to do anything to pop the valve. I've got the hammer spring maxed, so I think the hammer spring with such low air pressure basically isn't contributing hardly anything to precisely metering the air; hence my power wheel having pretty much no effect either, no matter where I set it. I'll run a chrono string at this low setting to document it but then raise the reg and start tuning anew.

This current tune is about 11 fpe.

Ideas appreciated. 🙂

Here's my current shot string:

#     FPS        FT-LBS     PF
10    876        11.59      5.96     
9     860        11.17      5.85     
8     857        11.09      5.83     
7     863        11.25      5.87     
6     846        10.81      5.75     
5     872        11.48      5.93     
4     876        11.59      5.96     
3     875        11.56      5.95     
2     843        10.73      5.73     
1     880        11.69      5.98     
Average: 864.80
StdDev: 13.14
Min: 843
Max: 880
Spread: 37 (4.3% not so good)
True MV: 864.80
Shots/sec: 0.14

[Marc In Iowa]

This next string is with the reg about 105 bar but with the caliber "power" set to Low so as to not overwhelm the GTOs.

#     FPS        FT-LBS     PF
10    797        9.59       5.42     
9     795        9.54       5.41     
8     801        9.69       5.45     
7     798        9.62       5.43     
6     800        9.67       5.44     
5     803        9.74       5.46     
4     802        9.71       5.45     
3     795        9.54       5.41     
2     803        9.74       5.46     
1     806        9.81       5.48     
Average: 800.00
StdDev: 3.68
Min: 795
Max: 806
Spread: 11 (1.4%, more like it!)
True MV: 800.00
Shots/sec: 0.16

Seems like it used more air though.

[RDB]

Looking good. Your getting more consistent dwell from the hammer strike now with the reg bumped up. Your extreme spread shows it.

[Marc In Iowa]

How low can you go ... on reg pressure?

I'm trying to tune for a very light pellet (177 GTO 6.8 grain). By setting the reg to about 60 bar, I was shooting about 860 fps but my fps variation was about 4.3%. Cranking the reg up to about 110 bar the variation was 1.4% (more like it!). But ... I had to choke down the valve to LOW power to shoot at 810 fps.

Is their a practical limit as to how low the AMP reg can be set? I notice Huma makes a Dreamline reg and says:

"...output pressure range is adjustable from 90-170 bar"

https://www.huma-air.com/FX-Dreamline-Power-Tuning-Regulator-Set

The AMP reg maxes out at 160 bar.

[JoeKool]

How low can you go ... on reg pressure?

I'm trying to tune for a very light pellet (177 GTO 6.8 grain). By setting the reg to about 60 bar, I was shooting about 860 fps but my fps variation was about 4.3%. Cranking the reg up to about 110 bar the variation was 1.4% (more like it!). But ... I had to choke down the valve to LOW power to shoot at 810 fps.

Is their a practical limit as to how low the AMP reg can be set? I notice Huma makes a Dreamline reg and says:

"...output pressure range is adjustable from 90-170 bar"

https://www.huma-air.com/FX-Dreamline-Power-Tuning-Regulator-Set

The AMP reg maxes out at 160 bar.

I believe you may have too much hammer spring tension for shooting  the .177 GTO pellets, and possibly too high of a regulator pressure.  You ideally want to be set at the correct caliber setting .177/.22 (transfer port) and MAX (hammer spring dial) that setting should give you you top desired speed.  Then every other lower external setting on your DreamPup could be used to incrementally shoot at lower velocities.

Try this tuning method:

With your AMP regulator set @ 110 bar (or any pressure setting you choose), your transfer port on .177/.22, and your hammer spring adjuster dial on the MAX setting. Remove the stock. Back the internal hammer tension grub screw out all the way until flush with the opposite side from where you place the allen key(see below pictures).  Re-install stock.  Then over the chronograph take a small shot string just to note what speed your shooting.

If this is too fast you need less regulator pressure.  If that proves to be too slow of a velocity you need more HS tension.  Keeping your transfer port and HS adjustments the same (.177/.22 & MAX).  Remove the stock again.  Increase the internal grub screw clockwise in half turn increments.  Re-install the stock.  Again take shots over the chronograph until your velocity is where you want it to be (your done).
 Note:  It’s important for efficiency not to have too much hammer spring tension (you’d waste air, lower shot count, and cause more air turbulence behind the pellet decreasing accuracy). 

Let’s say you are wanting to shoot at 830fps and using this method you chronograph @ a 840fps average.  Just back the grub screw out in quarter turns counter-clockwise until you’re back in the ballpark of 830fps (that would yield good efficiency).  You want just enough hammer spring tension to reach the desired velocity never more than necessary.  I’m guessing 830 to 850 fps with the GTO’s would be a good velocity area. Idk, probably the highest speed the GTO’s can handle and still give good accuracy.  I use .22 cal GTO’s (11.75gr) in my .22 DreamPup and they do well @ 830fps.

You could use this same method at what ever regulator pressure you choose.  Your goal would be to achieve your desired best  energy, velocity, accuracy, consistency  and efficiency.

There is no magic formula, you just have to experiment until you find what your happy with.  It’s a tedious task but the end results are worth it.  After a couple of tunes this becomes second nature.  Just have plenty of pellets, air, chronograph batteries, and a good set of allen keys.  Lol!

Wouldn’t go with the huma personally.  To make adjustments you would have to remove the air cylinder and the Huma regulator each time you wanted to change the pressure setting.  Unlike the FX AMP regulator which is easily adjusted up or down externally.  I have been using the AMP regulator in my DreamPup for almost a year, they are very consistent.  Just as consistent as the Huma regulator in my FX Streamline. You just have to tune correctly to find the sweet spot meaning the perfect balance point between your regulator pressure and hammer spring tension.  If you use the above methods you’ll get there sooner than later.

I’ve included pictures of the parts and pieces:

[Marc In Iowa]

I believe you may have too much hammer spring tension for shooting  the .177 GTO pellets, and possibly too high of a regulator pressure.

I believe that is correct. I had a very nice phone call with Earnest Rowe about my tuning challenges.

Bottom line:

The Dreamline powerplant design is really meant to deliver more power than what is needed for 6.8 grain pellets (~12 fpe). DL more for 24-30 fpe.

If I had chosen the .22 Dreamline, GTOs @ 900 fps is more like 21 fpe; a much better fit (as you know from your experience).

I'm not wedded to shooting .177 and almost ordered the .22 DL. I should have. Now, I need to figure out my options.

[RDB]

Maybe joe can confirm? Is there a hammer weight in your dreamline? If so, removing the weight would help getting you closer to what your after. Most guys add hammer weight to push the platform harder. Removing it would let you lower the reg pressure and and offset the spring tension.

[Marc In Iowa]

Is there a hammer weight in your dreamline?

Earnest mentioned going to a lighter hammer but I'm guessing there's no hammer weight to just remove.

[JoeKool]

I believe you may have too much hammer spring tension for shooting  the .177 GTO pellets, and possibly too high of a regulator pressure.

I believe that is correct. I had a very nice phone call with Earnest Rowe about my tuning challenges.

Bottom line:

The Dreamline powerplant design is really meant to deliver more power than what is needed for 6.8 grain pellets (~12 fpe). DL more for 24-30 fpe.

If I had chosen the .22 Dreamline, GTOs @ 900 fps is more like 21 fpe; a much better fit (as you know from your experience).

I'm not wedded to shooting .177 and almost ordered the .22 DL. I should have. Now, I need to figure out my options.

Try 60 to 70 bar regulator pressure, and back the hammer spring grub screw out like suggested above.  I guarantee this airgun can shoot @ 12 fpe.  Just needs the correct tuning settings.  The Uk versions are doing it and the only difference between those and the USA models is the UK models don’t allow you to adjust the regulator.  Also, the only difference in the .177 and the .22 model Dreamline is the barrel caliber and the pellet probe size.  And of coarse the factory settings for those caliber differences.

Ignore Gile’s silliness, but watch this video?

[Marc In Iowa]

... this airgun can shoot @ 12 fpe.

No doubt. If I were to use the LOW setting and 115 bar reg I could get it shooting about 850-880. I may yet tune it that way to test air usage.

To get the power really right, there are three mods I could do too.

1. Lighter hammer spring
2. Smaller main valve
3. Light hammer (Delrin?)

Although, tuning is not my excitement, I've tuned 3 unregulated airguns; Discovery, Urban and Bantam. Not so enjoyable. The Urban was the easiest. When I bought the Dreamline, I'd hoped to have a rifle with "dial-able" tuning without mods.

[JoeKool]

... this airgun can shoot @ 12 fpe.

No doubt. If I were to use the LOW setting and 115 bar reg I could get it shooting about 850-880. I may yet tune it that way to test air usage.

To get the power really right, there are three mods I could do too.

1. Lighter hammer spring
2. Smaller main valve
3. Light hammer (Delrin?)

Although, tuning is not my excitement, I've tuned 3 unregulated airguns; Discovery, Urban and Bantam. Not so enjoyable. The Urban was the easiest. When I bought the Dreamline, I'd hoped to have a rifle with "dial-able" tuning without mods.

No need to modify anything.  Everything you need is built right in it from factory to reach 12 fpe consistently and efficiently.  Knowing how is half the battle.  It’s like flying a airplane I have absolutely no idea how to do it, in fact that would terrify the life out of me.  But, to a trained pilot it’s like riding a bicycle.  You’ve purchased a darn fine airgun, just need to come to understand the tuning of it.

I’ve turned my DreamPup to shoot 23 grain slugs @ 905fps for 41fpe.  Now that required modifications.  It’s above the intended power of a .22 Dreamline.  But, you’re just powering it down.  Which is only a low reg pressure and removing some HS tension.  Why change more than you have to?

Back the circled grub screw out until flush?  Lower the regulator pressure about 60 to 70 and chronograph?  You lower the regulator correctly by turning the reg. adjuster screw clockwise only quarter turns at a time then dry firing a shot between each quarter turn adjustment.  To raise the regulator pressure just turn with small (very small) counter-clockwise until your regulator gauge is at the pressure you desire.

[Marc In Iowa]

Back the circled grub screw out until flush?  Lower the regulator pressure about 60 to 70 and chronograph?

Setting the reg to 60, I've done twice. I can certainly do it again (the online Dreamline PDF manual explains the process ... can't believe they're still shipping that old manual).

Earnest gave me a tip on how to set the grub screw to minimum. I'll try that and see how it goes. His opinion was the spring will still be too strong. We'll see the reality! 🙂

Not hard to try.

[Marc In Iowa]

... the only difference between those and the USA models is the UK models don’t allow you to adjust the regulator.

I wonder if they might have a weaker hammer spring too? It'd be easy enough for FX to do for those 12 fpe models.

Note these two springs for the UK.

https://spares.bagnallandkirkwood.co.uk/product/part-48-fx-dreamline-hammerspring/

I could always clip off a coil or two.

[RDB]

They used to omit the hammer weight on the UK models also. Its the part in front of the spring in Joe's picture.

[JoeKool]

... the only difference between those and the USA models is the UK models don’t allow you to adjust the regulator.

I wonder if they might have a weaker hammer spring too? It'd be easy enough for FX to do for those 12 fpe models.

Note these two springs for the UK.

https://spares.bagnallandkirkwood.co.uk/product/part-48-fx-dreamline-hammerspring/

I could always clip off a coil or two.

That could be the case.

[Marc In Iowa]

They used to omit the hammer weight on the UK models also. Its the part in front of the spring in Joe's picture.

I guess I would've thought this was "the hammer" but ... It's purpose is just to add additional weight to the hammer strike? Does it also serve as a spring guide?