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.
This system has largely been replaced by defining the weapon in terms of the measurement of the calibre, which is the standard today for most weapon systems in use by the world's armed forces.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:
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 | 94 mm | 3.7 inch |
Ordnance QF 60-pounder | Heavy field gun | 127 mm | 5 inch |
When used with British standard nomenclature:
In guns, particularly firearms, caliber is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matches that specification. It is measured in inches or in millimeters. In the United States it is expressed in hundredths of an inch; in the United Kingdom in thousandths; and elsewhere in millimeters. For example, a US "45 caliber" firearm has a barrel diameter of roughly 0.45 inches (11 mm). Barrel diameters can also be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Since metric and US customary units do not convert evenly at this scale, metric conversions of caliber measured in decimal inches are typically approximations of the precise specifications in non-metric units, and vice versa.
A breechloader is a firearm, in which the user loads the ammunition via the rear (breech) end of the barrel, as opposed to a muzzleloader, in which the user loads the ammunition via the front (muzzle) end of the barrel.
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres.
The Ordnance Quick-Firing 17-pounder was a 76.2 mm (3 inch) gun developed by the United Kingdom during World War II. It was used as an anti-tank gun on its own carriage, as well as equipping a number of British tanks. Used with the APDS shot, it was capable of defeating all but the thickest armour on German tanks. It was used to "up-gun" some foreign-built vehicles in British service, notably to produce the Sherman Firefly variant of the US M4 Sherman tank, giving British tank units the ability to hold their own against their German counterparts. In the anti-tank role, it was replaced after the war by the 120 mm BAT recoilless rifle. As a tank gun, it was succeeded by the 84 mm 20 pounder.
A rifled breech loader (RBL) is an artillery piece which, unlike the smoothbore cannon and rifled muzzle loader (RML) which preceded it, has rifling in the barrel and is loaded from the breech at the rear of the gun.
The Ordnance QF 25-pounder, or more simply 25-pounder or 25-pdr, was the major British field gun and howitzer during the Second World War. Its calibre is 3.45-inch (87.6 mm). It was introduced into service just before the war started, combining both high-angle and direct-fire abilities, a relatively high rate of fire, and a reasonably lethal shell in a highly mobile piece. It remained the British Army's primary artillery field piece well into the 1960s, with smaller numbers serving in training units until the 1980s. Many Commonwealth of Nations countries used theirs in active or reserve service until about the 1970s and ammunition for the weapon is currently being produced by Pakistan Ordnance Factories. Initial production was slow, but by 1945, over 12,000 had been manufactured. The 25-pounder was one of the most outstanding field artillery piece used by British and Commonwealth forces in the Second World War, being durable, easy to operate and versatile.
Naval artillery is artillery mounted on a warship, originally used only for naval warfare and then subsequently used for more specialized roles in surface warfare such as naval gunfire support (NGFS) and anti-aircraft warfare (AAW) engagements. The term generally refers to powder-launched projectile-firing weapons and excludes self-propelled projectiles such as torpedoes, rockets, and missiles and those simply dropped overboard such as depth charges and naval mines.
This article explains terms used for the British Armed Forces' ordnance (weapons) and ammunition. The terms may have slightly different meanings in the military of other countries.
A culverin was initially an ancestor of the hand-held arquebus, but later was used to describe a type of medieval and Renaissance cannon. The term is derived from the antiquated "culuering" and the French "couleuvrine" From its origin as a hand-held weapon it was adapted for use as artillery by the French in the 15th century, and for naval use by the English in the 16th century. The culverin as an artillery piece had a long smoothbore barrel with a relatively long range and flat trajectory, using solid round shot projectiles with high muzzle velocity.
The 7.5 cm KwK 42 L/70 was a 7.5 cm calibre German tank gun used on German armoured fighting vehicles in the Second World War. The gun was the armament of the Panther medium tank and two variants of the Jagdpanzer IV self-propelled anti-tank gun. On the latter it was designated as the "7.5 cm Panzerabwehrkanone 42" anti-tank gun.
The Armstrong RBL 7-inch gun, also known as the 110-pounder, was an early attempt to use William Armstrong's new and innovative rifled breechloading mechanism for heavy rifled guns.
A muzzle-loading rifle is a muzzle-loaded small arm or artillery piece that has a rifled barrel rather than a smoothbore. The term "rifled muzzle loader" typically is used to describe a type of artillery piece, although it is technically accurate for small arms as well. A shoulder arm is typically just called a "rifle", as almost all small arms were rifled by the time breechloading became prevalent. Muzzle and breechloading artillery served together for several decades, making a clear distinction more important. In the case of artillery, the abbreviation "RML" is often prefixed to the guns designation; a Rifled breech loader would be "RBL", or often just "BL", since smoothbore breechloading artillery is almost nonexistent. A muzzle loading weapon is loaded through the muzzle, or front of the barrel. This is the opposite of a breech-loading weapon or rifled breechloader (RBL), which is loaded from the breech-end of the barrel. The rifling grooves cut on the inside of the barrel cause the projectile to spin rapidly in flight, giving it greater stability and hence range and accuracy than smoothbore guns. Hand held rifles were well-developed by the 1740s. A popularly recognizable form of the "muzzleloader" is the Kentucky Rifle, which was actually developed in Pennsylvania. The American Longrifle evolved from the German "Jäger" rifle.
Naval artillery in the Age of Sail encompasses the period of roughly 1571–1862: when large, sail-powered wooden naval warships dominated the high seas, mounting a large variety of types and sizes of cannon as their main armament. By modern standards, these cannon were extremely inefficient, difficult to load, and short ranged. These characteristics, along with the handling and seamanship of the ships that mounted them, defined the environment in which the naval tactics in the Age of Sail developed.
An Armstrong gun was a uniquely designed type of rifled breech-loading field and heavy gun designed by Sir William Armstrong and manufactured in England beginning in 1855 by the Elswick Ordnance Company and the Royal Arsenal at Woolwich. Such guns involved a built-up gun construction system of a wrought-iron tube surrounded by a number of wrought-iron strengthening coils shrunk over the inner tube to keep it under compression.
A quick-firing or rapid-firing gun is an artillery piece, typically a gun or howitzer, which has several characteristics which taken together mean the weapon can fire at a fast rate. Quick-firing was introduced worldwide in the 1880s and 1890s and had a marked impact on war both on land and at sea.
The QF 6 pounder Nordenfelt was a light 57 mm naval gun and coast defence gun of the late 19th century used by many countries.
The BL 6-inch gun Marks II, III, IV and VI were the second and subsequent generations of British 6-inch rifled breechloading naval guns, designed by the Royal Gun Factory in the 1880s following the first 6-inch breechloader, the relatively unsuccessful BL 6-inch 80-pounder gun designed by Elswick Ordnance. They were originally designed to use the old gunpowder propellants but from the mid-1890s onwards were adapted to use the new cordite propellant. They were superseded on new warships by the QF 6-inch gun from 1891.
The BL 4-inch gun Mk I – Mk VI were a family of early British breech-loading 4-inch naval guns.
In artillery, caliber or calibre is the internal diameter of a gun barrel, or, by extension, a relative measure of the barrel length.
The 68-pounder cannon was an artillery piece designed and used by the British Armed Forces in the mid-19th century. The cannon was a smoothbore muzzle-loading gun manufactured in several weights, the most common being 95 long cwt (4,800 kg), and fired projectiles of 68 lb (31 kg). Colonel William Dundas designed the 112 cwt version in 1841 and it was cast the following year. The most common variant, weighing 95 cwt, dates from 1846. It entered service with the Royal Artillery and the Royal Navy and saw active service with both arms during the Crimean War. Over 2,000 were made and it gained a reputation as the finest smoothbore cannon ever made.