Hi, everybody! Let me introduce myself: Nikolay Boldov from Russia. Moscow, won Extreme Benchrest and American Field Target in 2019 (AZ, Extreme Benchrest) and 50 Yard Benchrest, One Gun Challenge in 2022 (AZ, Extreme Benchrest).
A few days ago, I’ve got my FX Panthera in .22 caliber. I consider this gun as a long range benchrest (150 yards) competition heavy slug (.22 40gr) shooter for my purposes.
My experience of slug shooting starts from 2017 when I began my experiments with 40gr slugs in .22 caliber, so I have a bit of experience in this topic.
I will try to describe my experiments, results, observations on this airgun in no-hype style with undoubtable (as much as possible) video proves here .
Technical details on FX Panthera can be found here: https://fxairguns.com/rifles/the-panthera/
Note: I’ve made a mistake saying that tungsten hummer is installed in my Panthera in my first post in social media about this gun. No tungsten hummers yet – just regular one, so this version is straight out of the box, no modification was made.
So, the very first thing I wanted to test is what speed and how many shots can this gun give me with it’s 300cc bottle and huge (156cc) plenum.
The result is 25 shots in 250-142 bar with 40gr slugs at the speed of 273 meters per second (896 fps). Average air consumption is 11,3 cubic centimeters of air per joule, that is a very good result as for me taking into account barrel length and projectile weight.
Here is the video prove and the table of calculations:
I’ve made my tests on 120 – 200 bar with the step of 10 bar and made 4 shots on each to get average velocity of that setting. I’m not sure if using regulator on the pressures above 170 bar is “legal” so don’t try to repeat.
Here is the chart of results that I’ve got (just to remind – 40gr .2185 slug)
You’ve got to take into account that the slugs I use are of rather big diameter - .2185 and of unusual shape – they are more like .22lr ammo. Usually slugs like H&N of the same weight gives +25-30 fps speed on the same settings (from my experience with FX Impact M3).
My intuition tells me that one of the most interesting setups for me (besides the one show in part one of that blog) will be the following:
175 bar reg pressure,
2,85 microwheel hammer settings
970 fps (294 meters per second) with my 40gr .2185 slugs
So, I decided to test that setup from 250 bar in the bottle and got 16 good shots. Here is the prove:
If everything goes fine, I plan to go outside and shoot at my shooting range tomorrow to at least 100 yards distance.
Past weekend was not the best to make accuracy tests outdoors, so I decided to have some tests and tuning indoors – in my workshop.
Is that a wise decision to use maximum hammer hit strike on lower reg pressures like 150 bar? Absolutely not. It will not increase the velocity of the projectile, but will raise your air consumption per shot to unreasonably high values. Here is what I’ve got during my test with reg pressure of 150 bar and 40gr .2185” slugs. 3 shots per every power settings were made and average result was put into the table.
So, as I got higher with micro wheel adjustment after 2.25 position, the sound of the shot became louder and the gun definitely vibrated much stronger every time. There is no need to go on higher hummer strike power – just the waste of air and destabilization of the projectile due to huge amount of useless air coming after it.
It is the simplest and obvious example of how it works. There is a curve of velocities going up, as we raise the hummer power from the lowest level, then you reach the maximum velocity and then stabilizing without any profits on velocity, but loss in air consumption. That is how it work with big plenums. Note: In case with low volume power plenum guns the curve will go down after the reached plateau of velocities if you will continue to increase hummer strike level.
I will not deny that there are some situations and reasons to go up to a bit higher hummer strike power after reaching the plateau, but it is the matter of very special purposes and should be done wisely with full knowledge of what you do and why.
A few days ago, I’ve got my FX Panthera in .22 caliber. I consider this gun as a long range benchrest (150 yards) competition heavy slug (.22 40gr) shooter for my purposes.
My experience of slug shooting starts from 2017 when I began my experiments with 40gr slugs in .22 caliber, so I have a bit of experience in this topic.
I will try to describe my experiments, results, observations on this airgun in no-hype style with undoubtable (as much as possible) video proves here .
Technical details on FX Panthera can be found here: https://fxairguns.com/rifles/the-panthera/
Part 1. First acquaintance with Panthera out of the box
I will not describe Panthera’s appearance and it's main features here (yet) as you can find it in other youtuber’s videos. I will share my tests and results here.Note: I’ve made a mistake saying that tungsten hummer is installed in my Panthera in my first post in social media about this gun. No tungsten hummers yet – just regular one, so this version is straight out of the box, no modification was made.
So, the very first thing I wanted to test is what speed and how many shots can this gun give me with it’s 300cc bottle and huge (156cc) plenum.
The result is 25 shots in 250-142 bar with 40gr slugs at the speed of 273 meters per second (896 fps). Average air consumption is 11,3 cubic centimeters of air per joule, that is a very good result as for me taking into account barrel length and projectile weight.
Here is the video prove and the table of calculations:
My first impression.
- I didn’t expect FX Panthera to be able to shoot those heavy slugs at that velocity (it should be rather accurate according to my experience) out of the box.
- I really didn’t think that it would be possible to make 25 rather consistent shots from 300cc bottle
- Really happy to have opportunity to shoot 40gr long (12,5mm / 0,5 inch) .22 slugs out of the box with usual magazine
- I didn’t think that it would be possible to shoot those speeds with usual tube-like probe. I had to use pin probe for that needs in all my previous airguns.
Part 2. Know your gun power abilities
The next step I’ve taken to get acquainted with my FX Panthera in a better way is knowing it’s power parameters. My thoughts were the following. Panthera has a huge power plenum of 156cc and it is not an easy task to take it all out during shooting (at least this comes out of my previous experience with this type of airguns). And my thoughts were that using MAX hammer spring tension is not a bad idea, because on high pressures I usually use, the hammer can barely harm the valve. So, there is nothing bad in setting the hammer to maximum power level (that is a bit above 4 micro wheel settings) and testing the gun on different regulator adjustments.I’ve made my tests on 120 – 200 bar with the step of 10 bar and made 4 shots on each to get average velocity of that setting. I’m not sure if using regulator on the pressures above 170 bar is “legal” so don’t try to repeat.
Here is the chart of results that I’ve got (just to remind – 40gr .2185 slug)
| Bar | Hammer set | Average velocity FPS | Average velocity meters per second |
| 120 | MAX | 827 | 252 |
| 130 | MAX | 860 | 262 |
| 140 | MAX | 892 | 272 |
| 150 | MAX | 909 | 277 |
| 160 | MAX | 938 | 286 |
| 170 | MAX | 958 | 292 |
| 180 | MAX | 975 | 297 |
| 190 | MAX | 995 | 303 |
| 200 | MAX | 1001 | 305 |
You’ve got to take into account that the slugs I use are of rather big diameter - .2185 and of unusual shape – they are more like .22lr ammo. Usually slugs like H&N of the same weight gives +25-30 fps speed on the same settings (from my experience with FX Impact M3).
My intuition tells me that one of the most interesting setups for me (besides the one show in part one of that blog) will be the following:
175 bar reg pressure,
2,85 microwheel hammer settings
970 fps (294 meters per second) with my 40gr .2185 slugs
So, I decided to test that setup from 250 bar in the bottle and got 16 good shots. Here is the prove:
If everything goes fine, I plan to go outside and shoot at my shooting range tomorrow to at least 100 yards distance.
Part 3. Be wise with your hummer strike power
Past weekend was not the best to make accuracy tests outdoors, so I decided to have some tests and tuning indoors – in my workshop.
Is that a wise decision to use maximum hammer hit strike on lower reg pressures like 150 bar? Absolutely not. It will not increase the velocity of the projectile, but will raise your air consumption per shot to unreasonably high values. Here is what I’ve got during my test with reg pressure of 150 bar and 40gr .2185” slugs. 3 shots per every power settings were made and average result was put into the table.
| Reg pressure | Micro adjustment | FPS | Meters per second |
| 150 bar | 1.25 | 584 | 178 |
| 150 bar | 1.5 | 686 | 209 |
| 150 bar | 1.75 | 793 | 242 |
| 150 bar | 2 | 883 | 269 |
| 150 bar | 2.25 | 915 | 279 |
| 150 bar | 2.5 | 915 | 279 |
| 150 bar | 2.75 | 922 | 281 |
| 150 bar | 3 | 922 | 281 |
| 150 bar | 3.25 | 918 | 280 |
| 150 bar | 3.5 | 918 | 280 |
| 150 bar | 3.75 | 918 | 280 |
So, as I got higher with micro wheel adjustment after 2.25 position, the sound of the shot became louder and the gun definitely vibrated much stronger every time. There is no need to go on higher hummer strike power – just the waste of air and destabilization of the projectile due to huge amount of useless air coming after it.
It is the simplest and obvious example of how it works. There is a curve of velocities going up, as we raise the hummer power from the lowest level, then you reach the maximum velocity and then stabilizing without any profits on velocity, but loss in air consumption. That is how it work with big plenums. Note: In case with low volume power plenum guns the curve will go down after the reached plateau of velocities if you will continue to increase hummer strike level.
I will not deny that there are some situations and reasons to go up to a bit higher hummer strike power after reaching the plateau, but it is the matter of very special purposes and should be done wisely with full knowledge of what you do and why.
Part 4. Brief review of FX Pantera and first try to shoot 40gr slugs to 100 yards
Part 5. RECORD?!?!?
Not much text this time - everything is in the video. 100 yards, .22 40gr slugs, 60 shots (6 groups by 10 shots) one by one without stop, single shutter made video as a prove - 0,97 MOA! It is not a hype - it is a fact. Amazed with FX Panthera stability, never met something like that before! Last edited:
