FX Caliber change and necessary parts Fx King

Melo

Member
Aug 25, 2024
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Caliber change and necessary parts Fx King .22 to .177.
I have a Fx King in .22 and a 600 mm barrel and I would like to change it to .177 while keeping the same barrel length and although I have seen several videos online on how to make the change,It's not entirely clear to me.

Looking for the necessary parts on the Fx airguns page, it seems that they sell a complete kit with several parts, the question is that in the videos that I have seen, to change the caliber they only change the FX Dynamics STX Tube to the desired size and caliber and the pellet probe. It seems that this kit also includes the plenum, the carbon liner, etc. If I only wanted to change the pellet probe and the barrel, I imagine that the rest of the parts of my rifle would be usable, liner, plenum, or when changing the caliber to a lower one I would need a smaller volume plenum.

Please, could someone with more experience than I have tell me what parts I need?
The pieces numbered 1, 2, 3 I think are not necessary because I still keep the same length.
Number 4 is the probe, yes change.
Parts 5, 6 and 7 yes, because for future changes I will have 2 complete barrels and will only require changing the probe and barrel.
I'm either right or wrong.


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Huma air sells a caliber change kit. I believe it comes with the breech/transfer port piece, probe and maybe the muzzle lock nut if that is needed for the different caliber. I can’t remember for sure if the lock nut was included or even needed 🤷‍♂️. Of course you would need a new liner. All your other original parts can be used if keeping same barrel length.
 
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