FX dreamline Tuning help

[DaveT1]

I've fallen down the FX tuning rabbit hole and need help getting out!
My goal is develop a tune that allows me to shift from 18.1 gr pellets to 20.2 gr slugs by just making changes to the power wheel and the transfer port.

GUN MODS: Base gun is an FX Dreamline Tact in .22 cal and 500 mm barrel. I have added: The 23 step power wheel. Huma heavy hammer spring. Huma 13 gram hammer weight. Huma dual port transfer port. Pin probe. FX superior liner w/CF sleeve. CF shroud. Donny FL FX moderator. I measure hammer spring pre-load by using a digital caliper on the side slot adjustment window.

What I'm attempting is the flattest chrono graph line possible (I'm using an FX chrono). With the reg set at 130 bar, the power wheel at 23, the pre-load at 15.4 mm and the transfer port set to .25/.30. The results for slugs is promising, less than a 10 fps spread and good accuracy. When I use the the same settings and turn the power wheel down to 7 I get similar results but the graph is more shark toothed; the shots jumping 10 fps up and down as opposed to the relatively flat line of the slugs. Another anomaly I'm seeing is that after 9-10 shots the speed drops 10-15 fps and slowly builds back.

I'm using the gun for long range target shooting (200-250 yards for slugs), so consistency is of prime importance. My question is: Am I trying to tune a unicorn? One gun that excels with both type of ammo. Since I obviously love to tinker, I'm willing to try any changes.

 

[Florida_Man]

Can it be done? Longshot, but possible. You’re asking a lot out of a 500mm barrel.
To be consistent at 200-250 like you want, I’d want a 700mm barrel and a heavier slug

 

[starlingassn]

imo yes,youre looking for a unicorn.

if you dont mind retuning when switching ammo then have at it.

 

[bfloyd1095]

Can it be done? Longshot, but possible. You’re asking a lot out of a 500mm barrel.
To be consistent at 200-250 like you want, I’d want a 700mm barrel and a heavier slug

I agree.
It takes a Lot more air with that 500mm barrel to achieve velocity, in turn you have the gun so "bound up" it's unhappy.
Going to the 700mm will allow you to unwind the gun and get it back to happy harmonics..

You will hear a huge difference in the shot once you do this and the numbers, curve, etc. will take care of itself

It is Very easy to crank the hell out of a gun and expect good results when in fact it is exactly the opposite effect, you will definitely know by ear when its getting close to being "happy"

 

[madeintheuk]

You’re not getting a prefect shot string out of 2 different settings at the same reg pressure. I wouldn’t worry too much about the spread, and more about accuracy. Shoot your slug setup, then shoot your pellets. See how accuracy is. If it’s there, leave it alone. People get so caught up in extreme spreads, and tuning for velocity, that they forget that accuracy is more important. Before regs, we had bell curves, and spreads were crazy, but we still seemed to have great accuracy for a number of shots anyway.

 

[swNCsw]

I've fallen down the FX tuning rabbit hole and need help getting out!
My goal is develop a tune that allows me to shift from 18.1 gr pellets to 20.2 gr slugs by just making changes to the power wheel and the transfer port.

GUN MODS: Base gun is an FX Dreamline Tact in .22 cal and 500 mm barrel. I have added: The 23 step power wheel. Huma heavy hammer spring. Huma 13 gram hammer weight. Huma dual port transfer port. Pin probe. FX superior liner w/CF sleeve. CF shroud. Donny FL FX moderator. I measure hammer spring pre-load by using a digital caliper on the side slot adjustment window.

What I'm attempting is the flattest chrono graph line possible (I'm using an FX chrono). With the reg set at 130 bar, the power wheel at 23, the pre-load at 15.4 mm and the transfer port set to .25/.30. The results for slugs is promising, less than a 10 fps spread and good accuracy. When I use the the same settings and turn the power wheel down to 7 I get similar results but the graph is more shark toothed; the shots jumping 10 fps up and down as opposed to the relatively flat line of the slugs. Another anomaly I'm seeing is that after 9-10 shots the speed drops 10-15 fps and slowly builds back.

I'm using the gun for long range target shooting (200-250 yards for slugs), so consistency is of prime importance. My question is: Am I trying to tune a unicorn? One gun that excels with both type of ammo. Since I obviously love to tinker, I'm willing to try any changes.

A Question for you kind Sir. LOL What line of thinking led to you believe picking a dreamline dream tac with a 500 mm barrel to shoot both slugs and pellets, and/plus slugs at said distances of 200 - 250 yards accurately ? The dreamline has some of the most restrictive airflow and internal porting of the whole line up from FX No? To me IMHO it would be like asking someone with COPD to blow up balloons for birthday parties for a living lol. There are other options that can breathe a lot easier for that task.

Not trying to be rude at all here but just curious why you picked this particular model to achieve your goals ?

 

[Spartan]

A Question for you kind Sir. LOL What line of thinking led to you believe picking a dreamline dream tac with a 500 mm barrel to shoot both slugs and pellets, and/plus slugs at said distances of 200 - 250 yards accurately ? The dreamline has some of the most restrictive airflow and internal porting of the whole line up from FX No? To me IMHO it would be like asking someone with COPD to blow up balloons for birthday parties for a living lol. There are other options that can breathe a lot easier for that task.

Not trying to be rude at all here but just curious why you picked this particular model to achieve your goals ?

^^^ This

I love the dreamline, and I think it's an incredible platform in general. It's been my favorite pesting daily driver for years now. Dare I even say....as a platform it's quite underrated, even for an FX gun

But a highly tuneable, long range heavy hitter it is not. Was never intended to be. Other FX guns fit that bill. So you might be spending quite a bit of time and money chasing that unicorn.

 

[DaveT1]

Thanks to all for your input. In answer as to why I chose the Dreamline, it was a matter of economics. It was what I could afford at the time. From there I got sucked into the rabbit hole of the Latest Gadget Syndrome. The result has been that I've stretched out to about 225 yds with 20.2 NSA's with consistent hits on an 8" fry pan and 2 liter soda bottles. At 150 yds. 4" gongs live in fear... Under 100 yds, it's a tack driver.

Essentially, this whole project has been my introduction to fine tuning airguns. For me, tuning is as much fun as shooting. And yes it's time to move on to something with a 700 mm barrel (can you say Panthera?).

I appreciate all of the support this forum offers.

 

[swNCsw]

Thanks to all for your input. In answer as to why I chose the Dreamline, it was a matter of economics. It was what I could afford at the time. From there I got sucked into the rabbit hole of the Latest Gadget Syndrome. The result has been that I've stretched out to about 225 yds with 20.2 NSA's with consistent hits on an 8" fry pan and 2 liter soda bottles. At 150 yds. 4" gongs live in fear... Under 100 yds, it's a tack driver.

Essentially, this whole project has been my introduction to fine tuning airguns. For me, tuning is as much fun as shooting. And yes it's time to move on to something with a 700 mm barrel (can you say Panthera?).

I appreciate all of the support this forum offers.

You have accomplished what a lot of others have failed at lol. You have definitely earned an A+for effort .

Thank you for answering the question I asked and I get that 100 percent LOL. I feel like when you do get another platform you will once again be able to test the limits of the platform and they do stretch out farther than the dreamline haha. Keep up the research and testing there is plenty of tinkering to keep you busy with the FX lineup haha lol.

Best of luck to you in your new fun and rabbit hole explorations in this Hobby that we share ! You Sir. are doing great.

 

[madeintheuk]

Just an fyi, doesn’t matter what magical next gun you buy, most pcp’s won’t do double tunes well. They will shoot just fine, but your spreads will look similar. That’s not the Dreamlines fault. It’s the nature of the beast. If you were able to get the slugs going the speed you wanted, and can still dial it down to pellet speeds and be accurate, why bother buying something new?
The dreamline is a great platform. Simple, reliable, and accurate. I personally will never get rid of mine.

 

[rcarlisle]

I've got my .177 DreamTac (with a 500mm barrel) shooting 3 different pellets in the sweet spot for accuracy, but it's really working hard get the 16gr Beasts up to speed. And the compromise in efficiency is substantial. It'll be going back to its factory tune, but it was a fine waste of pellets getting to this point.

 

[Rorymac]

How can i bring the fx reg pressure down to be happy at 60 bar or less?