Brocock/BRK Pathfinder XR barrel question…

While cleaning the barrel of my Pathfinder I noticed the muzzle ends 3.25“ from the end cap. There appears to be enough room for a 12-13“ barrel. Would there be any performance gains by adding a longer barrel? Particularly if keeping the “stock” regulator and HS settings. Seems like there’s room to bump up the power that way without increasing the OAL of the gun.

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