.30-06 Springfield
From Wikipedia, the free encyclopedia
The .30-06 Springfield cartridge (pronounced "Thirty aught six") is a .308 inch (7.62 mm) caliber rifle cartridge, also known as the 7.62 x 63 mm, that was introduced as the standard cartridge of the United States Army in 1906 (hence, the "-06") and used as the primary cartridge of the caliber into the 1960s, with notable use tapering off in the 1960s/early 1970s. It remains a popular civilian and hunting round.
It was developed from and superseded the nearly identical .30-03 cartridge (introduced three years prior), but had a slightly shorter casing and a higher velocity spitzer bullet. There were three main production runs of the round, that roughly correspond to large stocks built up during wars; the initial 30-06, the M1 ball and then the M2 ball.
The Springfield 1903 rifle, introduced alongside the earlier cartridge, was quickly modified to accept the .30-06. 30-06 went on to replace 6 mm Lee Navy round used by the Navy at that time, as well as remaining older cartridges such as the 30 US Army used in the Model 1892 Krag. The .30-06 remained the US Army's main cartridge for nearly 50 years before it was finally replaced by the 7.62 x 51 mm (commercially known as the .308 Winchester) with the official adoption of the M14 in 1954. However, the first M14s were not fielded until 1957, and the .30-06 remained in service into the 1970s, mainly as a machine gun cartridge.
It was used in the bolt-action M1903 Springfield and M1917 Enfield, the semi-automatic M1 Garand, the Browning Automatic Rifle (BAR), and numerous machineguns. It served the United States in both World Wars and in the Korean War, serving as the basis for dozens of commercial and wildcat cartridges. Its last major use by the US military was in Vietnam. The .30-06's power, combined with the ready availability of surplus firearms chambered for it, has made it a popular hunting cartridge. It is suitable for hunting large mammals such as deer, elk, and moose.
Contents |
[edit] Performance
The .30-06 is a powerful round designed in an age when 1000 yard (914 m) shots were expected. In 1906, the original .30-06 cartridge consisted of a 150 grain (9.7 g) flat base cupronickel jacketed bullet. After World War I, the United States military realized the need for better long range performance out of machine guns. Based on reports from Europe, a streamlined, 173 grain (11.2 g), boat tail, gilding-metal bullet was used. The .30-06 cartridge with the 173 grain (11.2 g) bullet was called the 'M1 Ball'.
Army practice was to use the oldest ammunition for practice and, therefore, older stocks of M1906 continued in use until exhausted in 1936. Once the new M1 began seeing widespread use, the US military realized that it was traveling beyond the safety limits of ranges constructed for the 1906 cartridge over the past 30 years. Rather than engage in massive construction projects, it was decided to switch back to the original profile bullet but utilizing a newer jacket material. Initially, this bullet was stained to match the color of the cupro-nickel jacket.
This 152 grain (9.8 g) flat base bullet without the stain was standardized in 1940 as the 'Ball, M2' cartridge. According to US Army Technical Manual 43-0001-27, M2 Ball specifications call for 2740 feet per second (835 m/s) velocity, measured 78 feet (24 m) from the muzzle. M2 Ball was the standard issue ammunition for use in US military rifles and machineguns until replaced by the 7.62 x 51 mm for the M14 and M60.
Commercially manufactured rifles chambered in .30-06 are popular for hunting. Current .30-06 factory ammunition varies in bullet weight from 110 to 220 grains (7.1 to 14.3 g) in solid bullets, and as low as 55 grains (3.6 g) with the use of a sub-caliber bullet in a sabot. Loads are available with reduced velocity and pressure as well as increased velocity and pressure for stronger firearms. The .30-06 ranks as one of the most popular sporting cartridges in the world.
[edit] US Military Cartridge Types
NOTE: .30-06 cartridges are also produced commercially with a plethora of different bullets and to a number of different specifications.
- Armor Piercing, M2
- This cartridge is used against lightly armored vehicles, protective shelters, and personnel, and can be identified by its black bullet tip.
- Armor Piercing Incendiary, T15/M14 and M14A1
- This cartridge is used, in place of the armor piercing round, against flammable targets. The tip of the bullet is colored with aluminum paint. The M14A1 featured an improved core design and incendiary charge.
- Ball, M1906
- This cartridge is used against personnel and unarmored targets, and can be identified by its silver-colored bullet. The M1906 has an 150 grain (9.7 g) projectile and flat base. Its jacket is a cupro-nickel alloy which was found to foul the bore quickly.
- Ball, M1
- The M1 has a 173 grain (11.2 g), nine-degree boat-tailed projectile designed for aerodynamic efficiency. Though it had a lower initial velocity, velocity and energy were greater at longer ranges due to its efficient shape. The jacket material was also switched to gilding metal to reduce fouling.
- Ball, M2
- With a 152 grain (9.8 g) bullet based on the profile of the M1906, this cartridge incorporated the gilding-metal jacket of the M1 projectile and had a higher muzzle velocity than either of the earlier cartridges.
- Blank, M1909
- This cartridge is used to simulate rifle fire. The cartridge is identified by having no bullet, and by a cannelure in the neck of the case which is sealed by red lacquer.
- Dummy, M40
- This cartridge is used for training. The cartridge has six longitudinal corrugations and there is no primer.
- Explosive, T99
- Development of a cartridge that contained a small explosive charge which more effectively marked its impact. Often referred to as an "observation explosive" cartridge, the T99 was never adopted.
- Incendiary, M1917
- Early incendiary cartridge, bullet had a large cavity in the nose to allow the material to more easily shoot forward on impact. Because of this the M1917 had a tendency to expand on impact. The M1917 had a blacked tip.
- Incendiary, M1918
- Variant of the M1917 with a normal bullet profile to comply with international laws regarding open-tipped expanding bullets.
- Incendiary, M1
- This cartridge is used against unarmored, flammable targets. The tip of the bullet is painted blue.
- Match, M72
- This cartridge is used in marksmanship competition firing, and can be identified by the word "MATCH" on the head stamp.
- Tracer, M1
- Tracer for observing fire, signaling, target designation, and incendiary purposes. The M1 has a red tip.
- Tracer, M2
- Tracer for observing fire, signaling, target designation, and incendiary purposes. Has a short burn time. The M2 originally had a white tip, but then switched to a red tip like the M1.
- Tracer, T10/M25
- Improved tracer over M1/M2. Designed to be less intense in terms of brightness than either the M1 or M2 tracers. The M25 had an orange tip.
- Rifle Grenade Cartridges, M1, M2, and M3/E1
- These cartridge are used in conjunction with the M1 (for the M1903 rifle), M2 (for the M1917 rifle), and the M7 series (for the M1 rifle) grenade launchers to propel rifle grenades. The cartridge has no bullet and the mouth is crimped. The differences between the three cartridges have to do with the powder charge and the subsequent range of the launched grenade. The M3E1 also featured an extended case neck.
[edit] Selected examples of United States Military firearms chambered for the .30-06 cartridge
- M1903 Springfield and variants, loading from stripper clips.
- Gatling gun, The U.S. Gatling guns were re-chambered for 30-06, the last round they would be changed over to before being declared obsolete and withdrawn from service.
- Model 1909 Machine Rifle, The Benet-Mercie light machine gun was chambered for 30-06.
- M1917 'Chauchat', The US used a mix of Chauchauts in 30-06 and 8 mm lebel.
- Lewis gun The US used a limited amount of Lewis guns chambered in 30-06 in both WWI and WWII.
- M1917 Enfield, also loading from stripper clips. Despite its name was actually based on Mauser, not Enfield bolt.
- M1917 Machine Gun water-cooled and M1919 Machine Gun air-cooled machine guns, feeding from belts
- M1918 Browning Automatic Rifle, loading from detachable magazines.
- Marlin machine gun. Similar to the Colt-Browning machine gun ('Potato Digger'), but without 'digger' piston, and used mainly on aircraft.
- M1 Garand, loading in an en bloc clip
- M1941 Johnson Rifle, feeding from an internal rotary magazine
- M1941 Johnson LMG, feeding from magazine
[edit] Sporting Cartridges Derived from the .30-06
The United States has a large number of wildcatters, or handloaders who experiment with cartridges and bullets as a hobby. Sometimes these wildcat cartridges become popular enough to be adopted by a large commercial a rifle maker and/or ammunition manufacturer. The .30-06 has been the basis of 4 mainstream cartridges which are widely used for hunting:
- .25-06 Remington, necked down to accept .257" diameter bullets
- .270 Winchester, necked down to accept .277" bullets
- .280 Remington, necked down to accept 7mm (.284") bullets
- .35 Whelen, necked up to accept .358" (9mm) bullets
The .30-06 was also shortened during development of the M-14 rifle to make the 7.62 × 51 mm NATO, a round that has spawned a long list of its own wildcats.
[edit] See also
- Caliber conversion sleeve
- List of rifle cartridges
- Table of pistol and rifle cartridges
- 7 mm caliber
