Panthera 500 for a first time FX owner

Introduction:
As someone who grew up shooting an air rifle (and a recurve bow), I shot a springer most of my life. Ten years ago, I bought my first pcp and shortly after my second pcp: an Air Arms S510 Xtra FAC (without the power wheel) that I still shoot to this day. Two weeks ago I had the chance to shoot an FX for the first time, a Panthera 500 in .22 shooting pellets. I thought Panthera’s were pure slug guns (and I’m not that interested in slugs). Turns out the 500 is geared more toward pellet shooting. In the end a very expensive round of shooting, as it caused me to buy a Panthera 500 in .25.

First thoughts:
The first shots came across as unusually quiet. Too quiet, even with a Donnyfl Tatsu at the end of the barrel. Measured the pellet speed at 152 m/s with FX 25.4 gr pellets. And that’s where it begins: I never had an airgun with tuning knobs and power wheels attached to it. Let alone something with tunable regulator pressures. Turns out YouTube is your friend in this matter.

Getting things up to speed:
Regulator pressure was set at 110 bar at the factory so I let the regulator alone thinking FX should know what they’re doing. Turning the power wheel to 13 and slowly increasing hammer spring tension with the barrel adjuster got me to 194 m/s with FX 25.4 gr pellets. At home I’m shooting at 25m and the accuracy wasn’t all that great. At the 50m range it fell apart even further. Weird flyers and pellets wobbling through the air. A single 250 bar fill barely made it through two magazines (32 pellets). Back at home switched to the heavy 34gr FX pellets. Accuracy leaped forward, although one pellet every magazine managed to stray every time and pellet speed dropped to 261 m/s with these heavy pellets.

After a few days of turning knobs I finally gave it two clicks less on the barrel adjuster and landed at 260 m/s average speed. Air consumption went down as I can now get two magazines with room to spare off a 230 bar fill (divers tank dropped to 230 bar). And the gun is a bit quieter now.

Tune settings:
IMG_1894.jpeg IMG_1895.jpeg
 
Introduction:
As someone who grew up shooting an air rifle (and a recurve bow), I shot a springer most of my life. Ten years ago, I bought my first pcp and shortly after my second pcp: an Air Arms S510 Xtra FAC (without the power wheel) that I still shoot to this day. Two weeks ago I had the chance to shoot an FX for the first time, a Panthera 500 in .22 shooting pellets. I thought Panthera’s were pure slug guns (and I’m not that interested in slugs). Turns out the 500 is geared more toward pellet shooting. In the end a very expensive round of shooting, as it caused me to buy a Panthera 500 in .25.

First thoughts:
The first shots came across as unusually quiet. Too quiet, even with a Donnyfl Tatsu at the end of the barrel. Measured the pellet speed at 152 m/s with FX 25.4 gr pellets. And that’s where it begins: I never had an airgun with tuning knobs and power wheels attached to it. Let alone something with tunable regulator pressures. Turns out YouTube is your friend in this matter.

Getting things up to speed:
Regulator pressure was set at 110 bar at the factory so I let the regulator alone thinking FX should know what they’re doing. Turning the power wheel to 13 and slowly increasing hammer spring tension with the barrel adjuster got me to 194 m/s with FX 25.4 gr pellets. At home I’m shooting at 25m and the accuracy wasn’t all that great. At the 50m range it fell apart even further. Weird flyers and pellets wobbling through the air. A single 250 bar fill barely made it through two magazines (32 pellets). Back at home switched to the heavy 34gr FX pellets. Accuracy leaped forward, although one pellet every magazine managed to stray every time and pellet speed dropped to 261 m/s with these heavy pellets.

After a few days of turning knobs I finally gave it two clicks less on the barrel adjuster and landed at 260 m/s average speed. Air consumption went down as I can now get two magazines with room to spare off a 230 bar fill (divers tank dropped to 230 bar). And the gun is a bit quieter now.

Tune settings:
View attachment 372153 View attachment 372152
Are you happy with your purchase?
 
Yes I'm happy with my purchase. If you're looking for an extreme powerhouse of an airgun, you're better off with the Panthera 600 or 700. I wasn't looking for a high power slug launcher. In retrospect the Panthera 600 might have been another fine option, due to the slug liner in that gun apparently doing just fine with 34 grain pellets.
I have been tinkering with my 500 a bit more today, setting the regulator at 115 bar and upping the hammer tension. The gun now shoots at 267 m/s average with an ES of 4 m/s and an SD of 1.4 m/s, resulting in just under 80 joules. Perfect for shooting outdoors in windy conditions.
 
Did some testing with lighter weight slugs today at 40m (had to shoot from shelter due to intermittent rain so no 50m).
I tested the FX hybrid 26gr, ZAN 26.5 and 28gr, H&N 28gr and JSB knockout MK1 33.49gr. JSB doesn't offer anything lighter so 33.49gr it is. I normally shoot FX 34gr pellet so all the slugs are lighter. Shot 40 slugs of each variant and ran a patch through the barrel after every type of slug.
Results weren't great. The ZAN slugs looked weathered and even a bit corroded. The 26.5gr variants locked up the magazine several times due to poor fit (photo bellow) and failed to feed about 2 to 3 times every magazine (10 shots). They also gave the poorest results, barely hitting the 14cmx14cm target.
The other ones gave better groupings than the ZAN's but still not good. 4cm to 5cm at 40m doesn't cut it for me. Shot two groups with 34gr pellets to confirm and both were the usual one big hole.

Average speeds over the last 20 shots:

SlugAverage (m/s)ES (m/s)SD (m/s)Average (ft/s)ES (ft/s)SD (ft/s)
FX Hybrid 26gr281103.19223310.2
ZAN 26.5gr28561.3935204.2
ZAN 28gr28082919266.6
H&n 28gr28141.4922134.6
JSB 33.49gr26461.8866205.9

IMG_1912.jpeg
 
I guess going from 115 bar to 120 on the reg is the next logical thing. The only issue is that the gun shoots really nice groups with 34gr pellets the way it's set up now.
If your reg is to low you will waste air because the valve is opening to much at the hit of the hammer. If your reg is to high the fps will decrease because the spring of the hammer will not open enough the valve.
 
If your reg is to low you will waste air because the valve is opening to much at the hit of the hammer. If your reg is to high the fps will decrease because the spring of the hammer will not open enough the valve.
Got the reg at 120 bar at the moment. Due to the bad weather testing was postponed a few days as my FX chrono had difficulties tracking the pellets in heavy rain.
 
Last edited:
This is the setting where my Panther hunter .25 Cal lives:

View attachment 377950View attachment 377949
Do you get some consistency with your Panthera at these settings? I couldn't get any consistency or accuracy with mine at 120 bar in combination with 34gr FX pellets. Turning the micro adjust above 2.75 didn't give me any extra velocity, only erratic POI shifts.
 
Do you get some consistency with your Panthera at these settings? I couldn't get any consistency or accuracy with mine at 120 bar in combination with 34gr FX pellets. Turning the micro adjust above 2.75 didn't give me any extra velocity, only erratic POI shifts.
To much hammer and not enough barrel
 
  • Like
Reactions: tibor
To much hammer and not enough barrel
I guess so. Back at 115 bar with the micro just over 2.5 and everything is back to normal. The velocities aren't as consistent as before, but everything needs to settle down for that.
While I was at the range I tried some 25.4gr FX pellets on the same settings, just out of curiosity. They were flying way too fast (over 290m/s), as expected, but the gun also got very loud. Probably due to the lower inertia of those lighter pellets allowing way more air into the barrel.
 
Do you get some consistency with your Panthera at these settings? I couldn't get any consistency or accuracy with mine at 120 bar in combination with 34gr FX pellets. Turning the micro adjust above 2.75 didn't give me any extra velocity, only erratic POI shifts.
My Panthera compact hunter .25 Cal is super accurate and consistent.

I have found two cons in mine:

- It has a slow leak.

- The trigger after best adjustments possible is far away of being good.
 
That slow leak seems something FX customer support should be able to take care of.
I haven't touched the trigger yet, as it seems fine to me. As long as it's better than the trigger on a Remington 700, I can live with it. ;) Out of a sample size of two Panthera 500's I must say there's some difference in how the triggers are set from the factory. Mine is set at a decent pull weight with a rather crisp break, but with noisy springs. The other one I shot was set heavier but still with a crisp break and without noisy springs. The Panthera is the only gun I have where I can hear the trigger springs compress while squeezing the shot off.
 
  • Like
Reactions: tibor
I decided to replace the o-rings holding the liner in place with a carbon sleeve (like the Panthera 600 and 700 have from the factory). When I took the shroud off, dirt fell out. The outside of the barrel and the spacer that centers the shroud were very dirty. I guess the shroud, just like a suppressor, collects dirt over time. If you have a Panthera it might be a good idea to check for grime under the shroud.
The carbon sleeve is a very tight fit. At some point I even shaved a little bit of carbon off while sliding the sleeve into the barrel. Very tight indeed! Side note: only one o-ring around the liner in my 500.
 
My Panthera compact hunter .25 Cal is super accurate and consistent.

I have found two cons in mine:

- It has a slow leak.

- The trigger after best adjustments possible is far away of being good.
I have three FX guns. Maverick, M3 and a Panthera. Oddly despite the linkage required, the Maverick has the nicest of the three triggers despite hours of tinkering and watching videos on tuning them.
None of the three get anywhere close to FX’s description of their triggers.
 
  • Like
Reactions: L.Leon
I have three FX guns. Maverick, M3 and a Panthera. Oddly despite the linkage required, the Maverick has the nicest of the three triggers despite hours of tinkering and watching videos on tuning them.
None of the three get anywhere close to FX’s description of their triggers.
I have a FX Streamline in .25 Cal. I bought it for my second son, who as soon as he saw my Daystate Huntsman requested an interchange.

So, I have a FX Streamline in .25 Cal and the trigger is really good !! I was waiting the Panthera to have a similar trigger but, unfortunately, not even close!
 
Last edited:
  • Like
Reactions: L.Leon
I have a FX Streamline in .25 Cal. I bought it for my second son, who as soon as he saw my Daystate Huntsman requested an interchange.

So, I have a FX Streamline in .25 Cal and the trigger is really good !! I was waiting the Panthera to have a similar trigger but, unfortunately, not even close!
Sadly my Maverick has a better trigger than my M3 or Panthera. Pathetic when you think about it.