FX FX Panthera tuning question

Air use per shot. You should record shot counts between high and low setting.

That ping noise is like when you take a hammer and hit the valve and it does not move as much. For example: take a hammer and hit a solid metal that wont move, a very high pitch noise will be made.
If you take a bigger hammer and hit it more the ping goes away. For example take a bigger hammer and drive that metal in, you will hear a dull metal to metal sound.
If you work with metal. You can tell when the object bottom out just by the noise of the hammer.

That ping tells you that the regulator pressure is to high for the low hammer setting.

BBRemedy said:

I’m new to the Panthera 700 and am learning to tune the beast. By the prior owner, it was previously set for Zan 30 slugs at 135 bar. It was no doubt consistent and accurate when I began to use it.

I then decided to try to tune it for JSB 18 pellets and followed multiple recommendations on the web to try 85 bar. At every power wheel setting the velocity was high, over 1000 fps. I progressively lowered the regulator pressure and finally reached 916 at about 60 bar, with a power wheel (hammer) micro setting of about 2, resulting in incredible consistency = 0.5 sd. Accuracy is rather impressive as well.

Now for the question…. Moving the power wheel through its range without changing the regulator pressure does not change the velocity more than a just few fps. However, as I test multiple power wheel settings, the sound emitted from the Panthera at the low end of the micro scale changes into a ping rather than a longer duration lower pitched sound.

What does that change in sound tell us about the tune?

Thanks in advance for your help. I appreciate this forum.

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BBRemedy said:

I’m new to the Panthera 700 and am learning to tune the beast. By the prior owner, it was previously set for Zan 30 slugs at 135 bar. It was no doubt consistent and accurate when I began to use it.

I then decided to try to tune it for JSB 18 pellets and followed multiple recommendations on the web to try 85 bar. At every power wheel setting the velocity was high, over 1000 fps. I progressively lowered the regulator pressure and finally reached 916 at about 60 bar, with a power wheel (hammer) micro setting of about 2, resulting in incredible consistency = 0.5 sd. Accuracy is rather impressive as well.

Now for the question…. Moving the power wheel through its range without changing the regulator pressure does not change the velocity more than a just few fps. However, as I test multiple power wheel settings, the sound emitted from the Panthera at the low end of the micro scale changes into a ping rather than a longer duration lower pitched sound.

What does that change in sound tell us about the tune?

Thanks in advance for your help. I appreciate this forum.

Click to expand...

When you hear the ping are you still achieving the desired velocity, accuracy and SD? If so, then there's no issue with hearing the ping. With low reg pressure the valve opens with a very light tap. More noise out of the barrel means wasted air. Bottom line - all else being equal (accuracy, velocity, SD) use the lightest hammer strike possible.

Hard to diagnose based on descriptions of sounds - which are pretty subjective.

Forget the macro (power wheel) and tune it only with the micro, starting with an even lower setting. Let’s say at 1.5 (I can’t recall how low it will go), speed is 800. Increase micro in 3 click intervals and monitor speed. At some point, it will max out at your given pressure. That’s the max speed for that pressure and projectile and a good tune would sit at a lower micro setting that gives 96% of that speed. So, if max is 930, dialing back 4% would leave the gun set at an optimal ~895. In reality you can settle at 95-97%, giving a little wiggle room to find optimal speed/accuracy. But, if you want to get to, say 950, you need to repeat the process after increasing reg pressure, such that peak speed is ~990. Conversely, if you wanted to go lower, say 850, you would reduce reg pressure and find the sweet spot that gives a peak speed of ~885. This process is the traditional “tuning on the knee”, to find a sweet combination of efficiency and resistance against the triad of reg misbehaviors (creep, input variation and slow refresh). With a 700barrel, I suspect you’re pretty close to the optimal pressure at 60bar. However, if the speed isn’t increasing with more hammer, it suggest that at 2 on the micro, you’re already at 100% (or over hammered) at the 60 bar.

Then, some folks actually favor tuning the Panthera to 99-100% on the curve. As a shortcut, you could just click the micro down by 5 and check that the speed decreases so you know that you’re not way over the plateau.

Either way, that seems like a very LONG solution to shooting 18.1s (and excuse the rough math)

60 bars seems incredibly low. No matter how soft the hammer hits that the valve will open wide and long and that might explain your lack of fps change.
I'd start with 110 bars , hammer at 1 and just up the hammer untill desired speed is reached.
Results will be a lot more logical i bet with a normal regulator pressure. In fact i might even start at 120 bar myself

100mtrbench said:

60 bars seems incredibly low. No matter how soft the hammer hits that the valve will open wide and long and that might explain your lack of fps change.
I'd start with 110 bars , hammer at 1 and just up the hammer untill desired speed is reached.
Results will be a lot more logical i bet with a normal regulator pressure. In fact i might even start at 120 bar myself

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In this respect I would like to share something here. I am shooting springers since I was a small boy but I am new to PCP’s.

Ten months ago I’ve purchased a Panthera .22 600 mm and some different types of pellets and slugs.

Pellets: JSB jumbo heavy 18.13, FX 18.1, H&N Baracuda match 21.14, JSB Jumbo Exact Monster Redesigned 25.39

Slugs: H&N 5.5 mm HP 25 grain (.218), Javelin Gen 2 5.5 mm 34 grain.

Tune 135 bar, 2.5 micro was shooting pellets JSB 25.39 redesigned, slugs H&N HP25 grain as well the Javelin Gen 2 34 grain in decent groups at 50 m. Unfortunately I was not able to register velocity in that situation…

Anyhow, installed the FX radar, loaded pellets JSB 18.13 pellet in the magazine at that tune resulted in velocity of ~1170 fps explaining the loudness upon the shot. Adjusted the macro half way down. Velocity dropped to ~1060 fps. Still high but I was able to hit 10’s with occasionally flyers.

Reading the forum I found a thread indication for pellet tune for the FX 18.1’s. I decided to try this for JSB 18.13’s and FX 18.1 grains.

So, degassed the gun, set reg setting at lower pressure (85 bars, micro 2.5) and it spitted out the pellets at ~982 FPS! 100 FPS more then listed at thread start?! Pellets grouped within 1”.

I adjusted micro down and speed dropped to minimum of of 880 FPS. Group stayed within 1”.

Out of curiosity decided to degas and drop regulator pressure significantly and start to increase speed gradually to see effect on grouping. At 50 bars, micro 2.5 at ~810 fps, pellets dropped on top of each other!

In a later stage I increased reg pressure to 85 bars again with micro 1.9 setting. Velocity went up to 989 FPS, close to previous setting at 85 bars. With this setting I shot 10 out of 10 at 50 mtrs. So no comments for accuracy at this tune combined with the FX 18.1 pellets!

My question to the experts here;

1. What do you think of the deviation 100 fps compared to tune as found in thread?
2. Can a very low (50 bars) regulator pressure do any harm?
3. Is the high velocity at the low pressure setting normal? (assuming the used FX radar is OK).
4. Any other comments?

Thank you in advance for potential replies and I hope that I can take learnings from them.

Take care.

Grtz, Jeroen

BBRemedy said:

At 65 bar (micro 2.5) with a 700mm barrel, my shots (18.13 JSB) averaged about 900 fps with a sd of less than 2 with great accuracy.

the longer the barrel, the lower the pressure in this case.

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Yes! But in my case it is a 600 mm and I only can get velocity below 900 fps at 50-55 bars with micro at lowest setting.

When going up a little with micro I am immediately back at the 900 region! I have not applied any modifications, it is still as supplied by the store. Strange in my opinion..

Any feed-back is welcome!

My wife just got me a 600mm .22 when Utah ran their sale. Can’t have it until Christmas though. Looking forward to setting it up for 50yd bench rest.