The .30-06 Springfield (pronounced thirty-aught-six or thirty-oh-six) (7.62×63mm in metric) was developed by the Springfield Armory for United States Army in 1906 and used until the late 1960s and early 1970s. The numerical designation was caliber first (.30) and year developed second, (06).
The .30-06 Springfield cartridge was chambered in rifles that served the United States in World Wars I and II, the Korean War, and the Vietnam Conflict. The now non-active duty cartridge has been fully replaced by the 7.62x51mm NATO cartridge. It is still in widespread use commercially.
Due to the large volumes of surplus military rifles and its popularity, the .30-06 Springfield has inspired dozens of commercial and wildcat cartridges.
The .30-06 Springfield cartridge started out life as the .30-03 Springfield, which was developed by Springfield Armory for United States Army in 1903 to replace the .30-40 Krag cartridge used in the Krag-Jørgensen rifle and new Springfield 1903 rifle. The .30-03 was also the first U.S. military cartridge to use smokeless powder. The .30-03 Springfield was also called the .30-45, since it used a 45 grain (2.9 g) powder charge, dating itself back to its old black powder roots.
At the turn of the century, much of the rest of the world was in the process of adopting the spitzer bullet. The light and more ballistically-efficient spitzer bullet was effective at greater ranges. The 03 was originally designed to use a 220 gr (14.3 g) round nose bullet. The cartridge was designed as a black powder cartridge, having a long neck which was the standard practice at the time. The Springfield Armory shortened the neck by 0.1 in (2.54 mm) and loaded the case with a 150 gr (9.7) spitzer type bullet with a muzzle velocity of 2700 ft/s (823 m/s).
Experience gained in World War I indicated that other nations' machine guns far outclassed American machine guns in maximum effective range. Additionally, long-range machine gun barrage or indirect fires were considered important in U.S. infantry tactics. As a result, the Ordnance Corps developed the .30 M1 Ball cartridge using a 174 gr (11.3) bullet with a 9 degree boat tail, traveling at a reduced muzzle velocity of 2640 ft/s (805 m/s). This cartridge offered significantly greater range for machine guns and rifles alike, due to its increased ballistic coefficient.
In 1936, it was discovered that the maximum range of the new M1 ammunition was beyond the safety limitations of many shooting and training ranges. An emergency order was made to manufacture quantities of ammunition that matched the ballistics of the older cartridge as soon as possible. A new cartridge was developed in 1938 that was essentially a duplicate of the old M1906 round, but with a gilding metal jacket and a different lead alloy, resulting in a bullet that weighed 152 gr (9.8 g ) instead of 150 (9.7 g). This cartridge, was designated “.30 M2 Ball” and used a flat-based bullet fired at a higher muzzle velocity 2,805 ft/s (853 m/s).
The .30-06 is a rimless cartridge. It uses a large rifle primer, and a .309 (7.84mm) caliber bullet (measured at the base). The bullet is 63mm long, and the cartridge's overall length (OAL) measures out to 3.34 inches.
U.S. Military cartridge typesEdit
Armor Piercing, M2Edit
This cartridge is used against lightly armored vehicles, protective shelters, and personnel, and can be identified by its black bullet tip. Bullet is flat base, weighs 163-168 grains.
Armor Piercing Incendiary, T15/M14 and M14A1Edit
This cartridge may be substituted for the M2 armor piercing round and is normally employed against flammable targets. The tip of the bullet is colored with aluminum paint. The M14A1 featured an improved core design and incendiary charge.
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 was found to quickly foul the bore.
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 changed to gilding metal to reduce fouling.
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 combined with a slightly heavier, pure-lead core. It had a higher muzzle velocity than either of the earlier cartridges.
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.
This cartridge is used for training. The cartridge has six longitudinal corrugations and there is no primer.
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.
Early incendiary cartridge, bullet had a large cavity in the nose to allow the material to more easily shoot forward on impact. As a result the M1917 had a tendency to expand on impact. The M1917 had a blackened tip.
Variant of the M1917 with a normal bullet profile to comply with international laws regarding open-tipped expanding bullets.
This cartridge is used against unarmored, flammable targets. The tip of the bullet is painted blue.
This cartridge is used in marksmanship competition firing, and can be identified by the word "MATCH" on the head stamp.
Tracer for observing fire, signaling, target designation, and incendiary purposes. The M1 has a red tip.
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.
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/E1Edit
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.