Calibre of a firearm is?
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 1/100' of an inch. Thus, caliber 22 means 22/100 inch= 0.22
Distance between a land and groove
Distance between two diagonally opposite lands
Distance between two diagonally opposite grooves
None