.303 British
From Wikipedia, the free encyclopedia
.303 British is a rifle and machine gun cartridge first developed in Britain in the 1880s as a blackpowder round, later adapted to use cordite and then smokeless powder propellant. It was the standard British and Commonwealth cartridge from 1889 until the 1950s, when it was replaced by the 7.62x51mm NATO round, and in the 1980s by the 5.56x45mm NATO in most roles. It is a rimmed cartridge and is therefore not entirely suitable for use in modern automatic weapons, but remains popular due to the large number of surplus military rifles chambered for the round which have been released to the civilian market, some of which have subsequently been modified for sporting use.
This cartridge saw much sporting use with surplus military rifles, especially in Australia and Canada. In Canada, it was found to be adequate for any game except the great bears.
Contents |
[edit] Mark I Solid Case
The Cartridge, S.A., Ball, Magazine Rifle, Mark I Solid Case, .303inch was first introduced with the Lee-Metford rifle in 1889. In its original form, the round was a 215-grain (13.9g) round-nosed cupro-nickel jacketed bullet propelled by 71.5 grains (4.63g) of RFG2 Blackpowder, giving it a muzzle velocity of 1830 feet per second (560m/s) and a chamber pressure of about 19 short tons force per square inch (260 MPa). Blackpowder is not very dense, and the charge had to be pressed into a solid pellet in order to fit inside the round. The rimmed cartridge made it easy to extract spent rounds from the chamber, although it did make them somewhat harder to stack in a magazine because the protruding rims would cause a jam if they were loaded incorrectly due to a double feed—that is the rim of the cartridge being fed by the bolt snagging the subsequent cartridge rim.
[edit] Mark 1 Cordite
Cordite was used as a propellant from 1891 and the first adopted cordite cartridge, the Cartridge S.A. Ball, Magazine Rifle Cordite Mark 1, used the same bullet but delivered 1970 ft/s (600m/s) at a chamber pressure of about 35,000 pounds per square inch (240 MPa). Small changes to the bullet jacket resulted in the Mark II of both the black powder and cordite versions, the Mark 2 and Mark 2.C respectively.
Nitrocellulose was first used as a propellant in 1894, but the higher temperatures and chemical activity was enough to make it unsuitable for use in the Lee-Metford, and the newer Lee-Enfield was introduced to address these problems. Although not officially adopted until 1916, nitrocellulose rounds were widely used during World War I, although cordite-loaded rounds were still produced for use in the tropics, where it was considered to be more stable.
[edit] Marks 3, 4, 5, 6
The round-nosed bullet was found to be unsatisfactory when used in combat, particularly when compared to the dum-dum rounds issued in limited numbers in 1897 during the Chitral and Tirah expeditions of 1897/98 on the North West Frontier of India. This led to the introduction of the Cartridge S.A. Ball .303 inch Cordite Mark 3, basically the original 215-grain (13.9g) bullet with the jacketing cut back to expose the lead in the nose. Similar hollow-point bullets were used in the Mark 4 and 5 rounds, the primary production versions. These highly effective soft-nosed and hollow-point bullets were later prohibited by the St Petersburg Declaration and the Hague Convention, and in 1903 they were withdrawn from active service and were afterwards to be used for target practice until stocks ran out. To replace them the Mark 6 round was introduced in 1904, using a round nose bullet similar to the Mark 2 but with a thinner jacket. It was generally agreed to be unsatisfactory.[citation needed]
[edit] Mark 7
In 1905 Mauser changed bullet design completely with the introduction of their "spitzer" rounds, the first of the classic design now referred to universally as "bullet shaped". In addition to being pointed, the round was also much lighter in order to deliver a higher muzzle velocity. It was found that as velocity increased the bullets suddenly became much more deadly.
In 1910, the British took the opportunity to replace their Mark 6 rounds with the new Mark 7 (Mark VII), using a 174-grain (11.3g) pointed bullet that gave a muzzle velocity of 2,440ft/s (740m/s)[1]. The Mark 7 was different to earlier .303 bullet designs or spitzer projectiles in general. Although the Mark 7 round looks like a conventional fully-metal jacketed bullet, this appearance is deceptive: its designers deliberately made the front third of the interior of the Mark 7 bullet out of aluminium or wood, instead of lead. This shifted the centre of gravity of the bullet towards the rear, making it tail heavy. Although the bullet was stable in flight due to the gyroscopic forces imposed on it by the rifling of the barrel, it behaved very differently upon hitting the target. As soon as the bullet hit the target and decelerated, its heavier lead base caused it to yaw severely and deform, thereby inflicting more destructive gunshot wounds than a standard spitzer design[[2]]. In spite of this, the bullet was legal according to the terms of the Hague Convention. The Mark 7 round remained the standard military cartridge for the remainder of the .303's service life.
Perhaps the most famous single .303 British round ever fired was on April 21, 1918, when Manfred von Richthofen, the famed Red Baron flying ace, was mortally wounded by a single .303 Mk 7 round.NOVA The shot was most likely fired from the ground, though there were three possible contenders: a Vickers machine gun on the ground, a pursuing fighter with a machine gun, and riflemen on the ground.
[edit] Mark 8
In 1938 the Mark 8 round was approved to obtain greater range from the Vickers machine gun. The primary change was the addition of a boat-tail and slightly more propellant, giving a muzzle velocity of 2,550ft/s (780m/s) and better ballistics.[citation needed] Chamber pressure was higher, at 40,000–42,000 lbf/in² (approximately 280 MPa). It was described as being for "All suitably sighted .303-inch small arms and machine guns" but caused significant bore erosion in weapons previously using cordite due to the channelling effect of the boat tail. As such it was prohibited from general use with rifles and light machine guns.[1] Using the Mark 8 the Vickers machine gun could fire effectively out to around 2.5 miles (4.1km).[citation needed]
[edit] Tracer, Armour-piercing and Incendiary
Tracer, armour-piercing and incendiary cartridges were introduced during 1915, and explosive bullets in 1916.[citation needed] These rounds were extensively developed over the years and saw several Mark numbers. The last tracer round introduced into British service was the G Mark 8 in 1945, the last armour-piercing round was the W Mark 1Z in 1945, and the last incendiary round was the B Mark 7 in 1942. Explosive bullets were not produced in the UK after 1933 due to the relatively small amount of explosive that could be contained in the bullet limiting their effectiveness, their role being successfully fulfilled by the use of Mark 6 and 7 incendiary bullets.
In 1935 the .303 O Mark 1 Observing round was introduced for use in machine guns. The bullet to this round was designed to break up with a puff of smoke on impact. The later Mark 6 and 7 incendiary rounds could also be used in this role if required.
During World War I British factories alone produced 7,000,000,000 rounds of .303 ammunition. Factories in other countries added greatly to this total.
[edit] Military Surplus Ammunition
Military surplus .303 British ammunition is often available, notably at gun shows. It may or may not have corrosive primers. Care must be taken to identify the round properly before purchase or loading into weapons. Cartridges with the Roman numeral VIII on the headstamp are the Mark 8 round, specifically designed for use in Vickers machine guns. Note that Mark 8 ammunition is not suitable for use in rifles because the boat-tailed design is certain to cause increased barrel wear. Advice to British soldiers was that Mark 8 ammunition should only ever be fired through rifles in an emergency situation ie when standard Mark 7 ammunition was unavailable.
[edit] Weapons chambered for .303 British
- Bren LMG
- Browning Model 1919 machine gun aircraft version
- Canadian Ross Rifle Mk I through III
- Charlton Automatic Rifle
- Lee-Enfield rifle
- Lee-Metford rifle
- Lewis gun
- Martini-Enfield rifle
- P14 rifle
- Vickers machine gun
- Vickers K machine gun
- Winchester Model 1895
- Parker-Hale Sporter Rifle
[edit] Specifications
- Maximum length:
- Case: 2.222 in (56.44mm)
- Overall: 3.04 in (77.2mm)
- Case trim length: 2.212 in (56.18mm)
- Primer type: Large rifle.
- Boxer or Berdan primed cases may be encountered.
- Rim thickness: 0.064 in (1.63mm)
- Rim diameter: 0.540 in (13.7mm)
- Case capacity (water): 55.7 grains (3.61g)
- SAAMI maximum pressure standard: 45,000 CUP (310 MPa) / 49,000 lbf/in² (338 MPa)
[edit] References
- ^ -IDENTIFICATION MANUAL ON THE .303 BRITISH SERVICE CARTRIDGE NO:1-BALL AMMUNTION, B.A.TEMPLE
