British military issue overpressure .338 Lapua Magnum cartridges with 70 mm (2.8 in) overall length, loaded with 16.2-gram (250 gr) LockBase B408 very-low-drag bullets fired at 936 m/s (3,071 ft/s) muzzle velocity from a L115A3 Long Range Rifle were used in November 2009 by British sniper Corporal of Horse (CoH) Craig Harrison to establish a new record for the longest confirmed sniper kill in combat, at a range of 2,475 m (2,707 yd) (since broken).

[4] In reports, CoH Harrison mentions the environmental conditions at Musa Qala were perfect for long-range shooting: no wind, mild weather, and clear visibility.

The .338 Lapua Magnum is capable of taking down any big game animals, though its suitability for some dangerous game (Cape buffalo, hippopotamus, white rhinoceros, and elephant) is arguable unless accompanied by a larger "backup" caliber: "There is a huge difference between calibers that will kill an elephant and those that can be relied upon to stop one.

"[6] In Namibia, the .338 Lapua Magnum in the past was legal for hunting Africa's big five game if the loads had at least 5,400 J (3,983 ft⋅lbf) muzzle energy.

Since 2015, Namibia and other sub-Saharan countries generally require larger minimal bore diameters by law for big-five hunting.

[7] In 1983, Research Armament Industries (RAI) in the United States began development of a new, long-range sniper cartridge capable of firing a 16.2-gram (250 gr), 0.338-inch-diameter (8.6 mm) bullet at 914 metres per second (3,000 ft/s), that could lethally penetrate five layers of military body armor at 1,000 m (1,094 yd).

of Bensenville, Illinois, to make the .338/416 or 8.58×71 mm cartridge cases, Hornady produced bullets, and RAI built a sniper rifle under contract for the U.S. Navy.

[10] The .338/416 rifle program was later canceled when the contractors were unable to meet the project's velocity target of 914 m/s (3,000 ft/s) for a 16.2 g (250 gr) bullet, due to excessive pressures rupturing cartridge cases.

The .338 Lapua Magnum fills the gap between weapons chambered for standard military rounds such as the 7.62×51mm NATO and large, heavy rifles firing the .50 BMG cartridge.

[13] It also offers an acceptable amount of barrel wear, which is important to military snipers who tend to fire thousands of rounds a year in practice.

[14] An appropriate fitting stock and an effective muzzle brake helps to reduce recoil-induced problems, enabling the operator to fire more rounds before getting too uncomfortable to shoot accurately.

[notes 2][15] Due to its growing civilian popularity, several high-quality tactical and match (semi) custom bolt actions designed for the .338 Lapua Magnum are becoming available.

Extremely thick-walled brass results in a 7.40 ml (114 grains H2O) cartridge case capacity for the .338 Lapua Magnum.

The exterior shape of the case was designed to promote reliable feeding and extraction in bolt action, semi-automatic, and automatic firearms alike, under extreme conditions.

(Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) decisions and tables edition 2007 the .338 Lapua Magnum case can handle up to 420.00 MPa (60,916 psi) Pmax piezo pressure.

decisions and tables edition 2003, that rated the .338 Lapua Magnum at 470.00 MPa (68,168 psi) Pmax maximum piezo pressure.

The American SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) has no normal voluntary guidelines for the .338 Lapua Magnum.

[76] For a typical .338 Lapua Magnum high-end factory military sniper rifle like the Sako TRG-42 with a 690 mm (27.2 in) long 305 mm (1 in 12 inch) rifling twist rate barrel at sea level, 1,500 m (1,640 yd) is considered to be the maximum shooting distance for man-sized targets.

When using standard Lapua military 16.2 g (250 gr) loads it has a supersonic range of 1,500 m (1,640 yd) under warm summer conditions at a muzzle velocity of 915 m/s (3,000 ft/s).

For significant supersonic range improvement, the aerodynamic efficiency of the employed bullets has to be significantly improved without sacrificing a lot of practically achievable muzzle velocity - meaning that besides the coefficient of drag of the projectile weight is also an important parameter for its actual downrange flight behavior.

Its most recent win (2007) was in an international special forces and police sniper competition in Switzerland against rifles chambered for 7.62×51mm NATO up to .50 BMG at ranges from 100 m – 1,500 m (109 yd – 1,640 yds).

Out of a 900 millimetres (35.4 in) long progressive twist barrel Möller expected to achieve 909 metres per second (2,982 ft/s) muzzle velocity.

certified, so it became an officially registered and sanctioned member of the Finnish "family" of super magnum rifle cartridges.

It is however still used by a few shooters who produce the cases from .338 Lapua Magnum brass by reshaping the shoulder and neck, and handloading it with .30 calibre bullets.

decisions and tables edition 2007, that rated the .300 Lapua Magnum at 470.00 MPa (68,168 psi) Pmax piezo pressure.

The 7.62 UKM was developed by Michael Uekötter and was C.I.P.-certified in 2002, making it an officially registered and sanctioned member of the Finnish "family" of super magnum rifle cartridges.

It is however still used by a few shooters who produce the cases from .338 Lapua Magnum brass by reshaping the shoulder and neck, and handloading it with .30 caliber bullets.

registered chambering introduced in 2021 and advertised by RUAG Ammotec as a cartridge that "fills the gap in ballistic performance between the .338 Lapua Magnum (8.6×70 mm) and the .50 BMG (12.7×99mm NATO)".

Because the .338 Lapua offers a large and exceptionally sturdy, pressure-resistant cartridge case that can be relatively easily reloaded and hence be reused several times, it has become quite popular amongst wildcatters.

Tom Sarver used a .300 Hulk wildcat cartridge, which is basically a necked-down, blown out, shortened .338 Lapua Magnum variant, to achieve a 1.403-inch (35.64 mm) diameter benchrest five-shot group on 7 July 2007, establishing a world record.