Calibre

Calibre. The diameter of the bore of a small arm or heavy gun. The calibres of the chief modern British firearms are as follows: - Magazine rifle: .303 inch. Guns: 111-ton, 16-25 inch; 67-ton, 13.5 inch; 45-ton, 12 inch; 29-ton, 10 inch; 22-ton, 9.2 inch; 14-ton, 8 inch; 5-ton, 6 inch; 40-cwt., 5 inch; 26-cwt., 4 inch; 20-pounder (12 cwt.), 3.4 inch; 12-pr. (7 cwt.), 3.0 inch; 9-pr. (6 cwt.), 3.0 inch; 7-pr. (3-1/2 cwt.), 2.5 inch. Quick-firing guns: 100-pr., 6 inch"; 45-pr., 4.7 inch; 9-pr., 2.6 inch; 6-pr., 2.24 inch; 3-pr., 1.85 inch; and 1-pr., 1.46 inch.