FX Crown .22 STX A liner Borescope

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This is a borescope of an FX Crown .22 showing the STX barrel and the function of the adjustable port. This liner is the "old type" pellet liner, that is to say not a slug liner and not the new FX superior liner. Initially this barrel suffered accuracy issues due to leading, and was treated with JB Bore compound, which resolved the issue. The barrel has been rarely cleaned, not for hundreds perhaps thousands of rounds, and has shot exclusively JSB pellets since its last several cleanings. Accuracy is excellent. One can assume this barrel has likely reached an equilibrium level of leading, where lead is shed at the same rate it accumulates. Also of note is how readily lead deposits flake off on the borescope.