Cartridge of the Week: The .30-06 Springfield


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The .30-06 Springfield

The .30-06 Springfield cartridge (pronounced "thirty-ought-six"), 7.62×63mm in metric notation and called ".30 Gov't '06" by Winchester, was introduced to the United States Army in 1906 and later standardized; it remained in use until the late 1970s. The ".30" refers to the caliber of the bullet in inches. The "06" refers to the year the cartridge was adopted, 1906. It replaced the .30-03, 6mm Lee Navy, and .30-40 Krag cartridges. The .30-06 remained the U.S. Army's primary rifle and machine gun cartridge for nearly 50 years before being replaced by the 7.62×51mm NATO and 5.56×45mm NATO, both of which remain in current U.S. and NATO service. It remains a very popular sporting round, with ammunition produced by all major manufacturers.

In the early-1890s, the U.S. military adopted the smokeless powder .30-40 Krag rimmed cartridge. The 1894 version of that cartridge used a 220-grain round-nose bullet. Around 1901, the U.S. started developing an experimental rimless cartridge for a Mauser action with box magazine. That led to the 1903 .30-03 rimless service round that used the same 220-grain round-nose bullet as the Krag. The .30-03 achieved a muzzle velocity of 2,300 ft/s.

Many European militaries at the beginning of the 20th century were adopting lighter-weight (roughly 150-to-200-grain), higher velocity, service rounds with pointed (spitzer) bullets: France in 1898 (8mm Lebel Balle D spitzer 198 grains with boat-tail), Germany in 1903 (7.92×57mm Mauser 153 grains S Patrone), Russia in 1908 (7.62×54mmR Lyokhkaya pulya), and Britain in 1910 (.303 British Mark VII 174 grains). Consequently, the round-nosed U.S. .30-03 service cartridge was falling behind. For these reasons, the U.S. military developed a new, lighter cartridge in 1906, the .30-06 Springfield, "cartridge, ball, caliber .30, Model of 1906", or just M1906. The .30-03 case was modified to have a slightly shorter neck to fire a spitzer flat-based 150-grain bullet that had a ballistic coefficient (G1 BC) of approximately 0.405, a muzzle velocity of 2,700 ft/s, and a muzzle energy of 2,429 ft⋅lbf.

The .30-06 cartridge was designed when shots of 1,000 yards were expected. In 1906, the original M1906 .30-06 cartridge consisted of a 150 grains, flat-base cupronickel-jacketed-bullet. After World War I, the U.S. military needed better long-range performance machine guns. Based on weapons performance reports from Europe, a streamlined, 173 grains boattail, gilding-metal bullet was used. The .30-06 cartridge, with the 173 grains bullet was called cartridge, .30, M1 ball. The .30-06 cartridge was far more powerful than the smaller Japanese 6.5×50mm Arisaka cartridge and comparable to the Japanese 7.7×58mm Arisaka. The new M1 ammunition proved to be significantly more accurate than the M1906 round. In 1938, the unstained, 150 grains, flat-base bullet combined with the .30-06 case became the M2 ball cartridge.

The M2 ball specifications required 2,740 feet per second minimum velocity, measured 78 feet from the muzzle. M2 ball was the standard-issue ammunition for military rifles and machine guns until it was replaced by the 7.62×51mm NATO round in 1954. For rifle use, M2 ball ammunition proved to be less accurate than the earlier M1 cartridge; even with match rifles, a target group of 5 inches diameter at 200 yards using the 150-grain M2 bullet was considered optimal, and many rifles did not perform nearly as well. The U.S. Marine Corps retained stocks of M1 ammunition for use by snipers and trained marksmen throughout the Solomon Islands campaign in the early years of the war.

Commercially manufactured rifles chambered in .30-06 are popular for hunting. Current .30-06 factory ammunition varies in bullet weight from 109.6 to 220.7 gr in solid bullets, and as low as 55.6 gr 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. Many hunting loads have over 3,000 foot-pounds of energy at the muzzle and use expanding bullets that can deliver rapid energy transfer to targets.