British standard ordnance weights and measurements
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 when the metric system was additionally introduced.
This system has largely been replaced by a calibre system, which is the standard today for most weapon systems in use by the world's armed forces.
The 18th century standards were based on projectile weight, and dated back to use of muzzle loaded cannons which fired solid cannonballs. The designations bore 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:
| Name | Type | Calibre | |
|---|---|---|---|
| Metric | Imperial | ||
| Ordnance QF 1 pounder "pom pom" | Infantry gun/AA gun | 37 mm | 1.457 inch |
| Ordnance QF 2 pounder | Anti-tank gun | 40 mm | 1.575 inch |
| Ordnance QF 2 pounder "pom pom" | Anti-aircraft gun | 40 mm | 1.575 |
| Ordnance QF 3 pounder Vickers | Naval gun | 47 mm | 1.85 inch |
| Ordnance QF 6 pounder | Anti-tank gun | 57 mm | 2.244 inch |
| Ordnance BL 10 pounder Mountain gun | Mountain gun | 69.8 mm | 2.75 inch |
| 12 pounder (multiple types) | Light field gun | 76.2 mm | 3 inch |
| Ordnance QF 13 pounder | Light field gun | 76.2 mm | 3 inch |
| 15 pounder (multiple types) | Field gun | 76.2 mm | 3 inch |
| Ordnance QF 17 pounder | Anti-tank gun | 76.2 mm | 3 inch |
| Ordnance QF 18 pounder | Field gun | 83.8 mm | 3.3 inch |
| Ordnance QF 20 pounder | Tank gun | 83.8 mm | 3.3 inch |
| Ordnance QF 25 pounder | Gun-howitzer | 87.6 mm | 3.45 inch |
| Ordnance QF 32 pounder | Tank gun | 96 mm | 3.78 inch |
| Ordnance QF 60 pounder | Heavy field gun | 127 mm | 5 inch |
Terminology
When used with British standard nomenclature:
- BL is short for "Breech Loading";
- ML is short for "Muzzle Loading";
- PR is short for "Pounder", e.g. 20 Pounder can be shortenned to "20-PR";
- QF is short for "Quick Firing", indicating the weapon is breach-loaded using cartridge casings, allowing faster loading and firing..
See also
References
- Rottman, Gordon L.: Elite 124 - World War II Infantry Anti-Tank Tactics, Osprey publishing, ISBN 1-84176-842-1 p. 16