.30-06 Springfield





The .30-06 Springfield cartridge (pronounced “thirty-ought-six” or "thirty-oh-six") is a 7.62 mm (.308 in.) calibre rifle cartridge, or 7.62 x 63mm, introduced to the United States Army in 1906 (hence “06”) and standardized, used until the 1960s and early 1970s.

It was developed from and superseded the nearly identical .30-03, having a slightly shorter case neck but identical overall length, and a higher velocity spitzer bullet.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 the M2 Ball.

The M1903 Springfield rifle, introduced alongside the earlier cartridge, was quickly modified to accept the .30-06. It replaced the 6 mm Lee Navy as well as remaining older calibers such as the .30 United States Army (also called .30-40 Krag) used in the Model 1892 Krag. The .30-06 remained the United States Army's main cartridge for nearly 50 years before it was finally replaced by the 7.62 x 51 mm (7.62mm NATO, commercial .308 Winchester) with the 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 rifle, the semi-automatic M1 Garand, the Browning Automatic Rifle (BAR), and numerous machine guns, including the M1919 series. It served the United States in both World Wars and in the Korean War, its last major use being in Vietnam. Large volumes of surplus brass made it the basis for dozens of commercial and wildcat cartridges, as well as being extensively used for reloading. The .30-06's power, combined with the ready availability of surplus firearms chambered for it, and so demand for commercial ammunition, has made it a popular hunting round. It is suitable for large mammals such as deer, elk, and moose.

Performance
The .30-06 is a powerful cartridge designed when 1.0 km (1100 yards) shots were expected. In 1906, the original .30-06 cartridge consisted of a 9.7 g (150 grain), flat-base cupronickel-jacketed-bullet. After WWI, the U.S. military needed better long-range performance machine guns. Based on weapons performance reports from Europe, a streamlined, 11.2 g (173 grain), boat tail, gilding-metal bullet was used. The .30-06 cartridge, with the 11.2 g bullet was called the "M1 Ball".

Army practice was to use the oldest ammunition for training, so old stocks of M1906 were used until 1936. Once the new M1 began to be used, the military saw that it went past the safety limits of firing ranges built for the 1906 cartridge in the previous thirty years. Rather than rebuild, the military returned to the original profile bullet, but utilizing a new jacket. Initially, it was stained to match the cupro-nickel jacket.

In 1940, the unstained, 9.8 g (152 grain), flat-base bullet became the standard "Ball, M2" cartridge. According to U.S. Army Technical Manual 43-0001-27, M2 Ball specifications require 835 m/s (2,740 feet per second) velocity, measured 24 m (78 feet) from the muzzle. The M2 Ball was the standard-issue ammunition for military rifles and machine guns until it was replaced by the 7.62 x 51mm 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 7.1 g to 14.3 g (110 to 220 grains) in solid bullets, and as low as 3.6 g (55 grains) 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 remains one of the most popular sporting cartridges in the world.

Cartridge dimensions
The .30-06 Springfield has 4.43 ml (68.2 grains) H2O cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions.



.30-06 Springfield maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans defined the shoulder angle at alpha/2 = 17.5 degrees. The common rifling twist rate for this cartridge is 254 mm (1 in 10 in), 4 grooves, Ø lands = 7.62 mm, Ø grooves = 7.82 mm, land width = 4.49 mm and the primer type is large rifle.

According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) guidelines, the .30-06 Springfield case can handle up to 405 MPa (58,740 psi) piezo pressure. In CIP-regulated countries, every rifle cartridge combination has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

The .30-06 Springfield is a Delta L problem cartridge, meaning it can present unexpected chambering or feeding problems. For more details, see Delta L problem.

The 8x64mm S is probably the closest European ballistic twin of the .30-06 Springfield. The 8x64mm S was intended as a ballistic upgrade option for the Mauser Gewehr 98 rifles that were then standard issue in the German military. The German military chose to keep their 8x57mm IS rifle cartridge, avoiding rechambering their service rifles for a larger and heavier cartridge.



.30-06 Springfield cartridge dimensions. All sizes in inches (in).

U.S. military cartridge types
NOTE: .30-06 cartridges are also produced commercially with many 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 a 9.7 g (150 grain) projectile and flat base. Its jacket is a cupro-nickel alloy which quickly fouls the bore.


 * Ball, M1
 * The M1 has a 11.2 g (173 grain), 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 9.8 g (152 grain) 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 blackened 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.

Selected examples of United States Military firearms chambered for the .30-06 cartridge



 * M1903 Springfield rifle 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 Chauchats in 30-06 and 8mm Lebel.
 * Lewis gun The US used a limited amount of Lewis guns chambered in 30-06 in both WWI and WWII.
 * 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 rifle, loading in an en bloc clip.
 * M1941 Johnson Rifle, feeding from an internal rotary magazine.
 * M1941 Johnson LMG, feeding from magazine.

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 rifle maker and/or ammunition manufacturer. The .30-06 has been the basis of several mainstream and wildcat cartridges which are widely used for hunting and other special applications:


 * .25-06 Remington, necked down to accept 6.53 mm (.257") diameter bullets
 * .270 Winchester, necked down to accept 7.04 mm (.277") bullets
 * .280 Remington, necked down to accept 7.21 mm (.284") bullets with the shoulder moved up slightly
 * 8mm-06, necked up to accept a 8.20 mm (.323") bullet. This is a common modification performed to German Mauser rifles to facilitate use of a in the USA more commonly available cartridge case with improved performance compared to the standard German 8x57mm.
 * .338-06, necked up to accept 8.59 mm (.338") diameter bullets
 * .35 Whelen, necked up to accept 9.09 mm (.358") bullets

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Cartridge:rifles