What is the meaning of "FX"...?
After reading some recent posts (cf. below), I've been wondering if there is a hidden meaning behing the brand name....
Could it be something like: "
For
Xareful shooter only"?
Before I receive a flood of hate mail and hate posts, please allow me to explain.

When I got into airgunning I was considering to buy a Gauntlet.
Due to its price category it had some shortcomings, no surprise there — the
big barrel bugaboo.... caused
significant POI shifts — because a slight bump to the barrel, or leaning it against a tree.
That was THE DEAL BREAKER for me — because when I hunt and take my rifle on hikes and the like — I can't use a rifle the is
only For
Xareful shooters that never bump the barrel.
Just
one Gauntlet quote:
The HUGE bugaboo has always been
the POI shifts. Shoots tight groups.... you just never know where the next tight group will be.
SOURCE:
https://www.airgunnation.com/topic/the-umarex-gauntlet-an-exercise-in-frustration-mixed-with-amazing-performance/#post-623774
Now if you would please forgive a gullible, simple-minded airgunner like me for thinking the following:
"If I spend FOUR TIMES as much money on a PCP than on the Gauntlet —
in that price category I surely will only get rifles that
don't have such fatal problems as POI shifts."
Now just imagine my surprise when I read posts like the following:

Yesterday I would dry fire the rifle 5 times before I started shooting at targets.
The POI was off and I had to correct with turret movement.
Got it dialed in and it was darn near hole in hole at 50 yards. I then shifted to another target and guess what!
My POI had shifted. 
The problem has to be
that long unsupported barrel and shroud. A slight bump of the bottle when using a barrel band or from a slight pressure on the shroud from any source transmits through the mechanics to the barrel and it's anchoring.
One would think FX has heard about this issue and would provide an aftermarket fix, under warranty.
I have learned that lots of folks experience the same calamity. Some are lucky and for some reason it doesn't happen with their same model of rifle.
SOURCE:
https://www.airgunnation.com/topic/observations-about-my-pcps/page/2/#post-683246
The mentioned thread has more testimonies about the
For Xareful shooters only guns. In fact, the other forums I frequent report the same.
One more link:
https://www.airgunnation.com/topic/fx-impact-x-mkii-unable-to-maintain-zero/ 
➔ ➔ ➔ ➔ ➔

I really like the looks of many of the guns FX produces, I really do! I'm not an FX-Hater at all!
But I need to realize: High-end airguns get their
big publicity not from hunters videoing squirrel kills in the woods or farmers on a pesting drive.
They get their big publicity from reports and posts about
winning a competition (EBR & Co) — which are great
For
Xareful shooters as they can baby the guns there.
Ergo, my personal conclusion from this (doesn't have to be
your conclusion, you get your very own, my friend!

):
My type of shooting does not allow me to baby my guns. So, I won't be buying guns that are only
For
Xareful shooters — and to be clear — this is not so much about a brand name but about
thin long free-floating barrels....
I think we need to warn newbees to our hobby about this...! Matthias