Small arms recalibration was one of the regular duties of a Starfleet officer with combat experience, and involved retuning weapons such as phasers and phaser rifles.
In 2373, Lieutenant Commander Worf was the ranking combat officer on Deep Space 9 and had the task of small arms recalibration. When Worf was put on detached service with the Klingon Defense Force, the task fell to Chief Miles O'Brien as he was the next highest ranking experienced combat officer. (DS9: "Soldiers of the Empire")