<prompt> Calibre of a firearm is?Distance between a land and grooveDistance between two diagonally opposite landsDistance between two diagonally opposite groovesNone  <response>: Distance between two diagonally opposite lands REF: Parikh 6th edition page 4.26 Caliber technicically means diameter of the inside of the bore land to land in 1100 of an inch. Thus, caliber 22 means 22100 inch 0.22 