British standard ordnance weights and measurements

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The British standard ordnance weights and measurements for the artillery were established by the Master General of Ordnance in 1764, and these were not altered until 1919, [ citation needed ] when the metric system was additionally introduced.

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This system has largely been replaced by defining the weapon in terms of the measurement of the calibre, which is the standard today for most weapon systems in use by the world's armed forces.

The 18th century standards were based on a projectile's weight, which dates back to use of muzzle loaded cannons that fired solid cannonballs. The bore designations are only an approximate relationship to the actual weight of the projectile when it was applied to modern artillery.

The table below lists the metric and Imperial calibres of various British weapons, which utilised the standard after 1919:

NameTypeCalibre
MetricImperial
Ordnance QF 1-pounder "pom pom" Infantry gun/AA gun37 mm1.457 inch
Ordnance QF 2-pounder Anti-tank gun40 mm1.575 inch
Ordnance QF 2-pounder "pom pom" Anti-aircraft gun40 mm1.575
Ordnance QF 3-pounder Vickers Naval gun47 mm1.85 inch
Ordnance QF 6-pounder Anti-tank gun57 mm2.244 inch
Ordnance BL 10-pounder Mountain gun Mountain gun69.8 mm2.75 inch
12-pounder (multiple types) Light field gun76.2 mm3 inch
Ordnance QF 13-pounder Light field gun76.2 mm3 inch
15- pounder (multiple types) Field gun76.2 mm3 inch
Ordnance QF 17- pounder Anti-tank gun76.2 mm3 inch
Ordnance QF 18- pounder Field gun83.8 mm3.3 inch
Ordnance QF 20-pounder Tank gun83.8 mm3.3 inch
Ordnance QF 25-pounder Gun-howitzer87.6 mm3.45 inch
Ordnance QF 32-pounder Tank gun94 mm3.7 inch
Ordnance QF 60-pounder Heavy field gun127 mm5 inch

Terminology

When used with British standard nomenclature:

See also

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<span class="mw-page-title-main">Ordnance QF 17-pounder</span> Anti-tank gun and tank gun

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