.338 Lapua
Encyclopedia
The .338 Lapua Magnum is a specialized rimless bottlenecked centerfire cartridge
Cartridge (firearms)
A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

 developed for military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 long-range sniper rifle
Sniper rifle
In military and law enforcement terminology, a sniper rifle is a precision-rifle used to ensure more accurate placement of bullets at longer ranges than other small arms. A typical sniper rifle is built for optimal levels of accuracy, fitted with a telescopic sight and chambered for a military...

s. The Afghanistan War
War in Afghanistan (2001–present)
The War in Afghanistan began on October 7, 2001, as the armed forces of the United States of America, the United Kingdom, Australia, and the Afghan United Front launched Operation Enduring Freedom...

 and Iraq War made it a combat-proven round with ready and substantial ammunition availability. The .338 Lapua is a dual-purpose anti-personnel and anti-materiel
Anti-materiel rifle
An anti-materiel rifle is a rifle that is designed for use against military equipment rather than against other combatants ....

 round; however, its anti-materiel potential is limited, due to the bullet's lower kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...

 compared with that of the .50 BMG
.50 BMG
The .50 Browning Machine Gun or 12.7×99mm NATO is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s. Entering service officially in 1921, the round is based on a greatly scaled-up .30-06 cartridge...

's 35.64 to 55.08 g (3.20763207632076E-06 to 4.95724957249572E-06 gr) projectiles. The loaded cartridge is 14.93 mm (0.587795275590551 in) in diameter (rim) and 93.5 mm (3.7 in) long. It can penetrate better-than-standard military body armour at ranges up to 1000 metres (1,094 yd) and has a maximum effective range of about 1750 metres (1,913.8 yd). Muzzle velocity is dependent on load and powder temperature and varies from 880 metre per second for commercial loads with 16.2 gram (1.4580145801458E-06 gr) bullets, which results in about 6525 J (4,812.6 ft·lbf) of muzzle energy.

Non-C.I.P.
Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives is an international organisation whose members are 14 states, mainly European....

 conforming British military issue overpressure .338 Lapua Magnum cartridges with a 91.4 mm (3.6 in) overall length, loaded with 16.2 gram (1.4580145801458E-06 gr) LockBase B408 very-low-drag bullet
Very-low-drag bullet
Very-low-drag bullets are primarily a small arms ballistics development of the 1980s–1990s, driven by shooters' desire for bullets that will give a higher degree of accuracy and kinetic efficiency, especially at extended ranges. To achieve this the projectile must minimize air resistance in flight...

s were used in November 2009 by British sniper Corporal of Horse
Corporal of Horse
Corporal of horse is a rank in the British Army's Household Cavalry corresponding to sergeant in other regiments. Formerly, no cavalry regiments had sergeants, but the Household Cavalry are the only ones to keep this tradition alive. It is said to stem from the origin of the word sergeant, which...

 (CoH) Craig Harrison
Craig Harrison (sniper)
Craig Harrison is a Corporal of Horse of the Household Cavalry of the British armed forces, and holds the record for the longest confirmed sniper kill in combat, at a range of...

 to establish a new record for the longest confirmed sniper kill in combat
Longest recorded sniper kills
Reports regarding the longest recorded sniper kill that contain information regarding the shooting distance and the identity of the sniper have been presented to the general public since 1967. Snipers in modern warfare have had a long history since the development of long distance weaponry...

, at a range of 2475 m (2,707 yd).

In addition to its military role, it is increasingly used by hunters and civilian long-range shooting enthusiasts. The .338 Lapua Magnum is capable of taking down any game animal, though its suitability for some dangerous game (Cape buffalo, hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...

, white rhinoceros
Rhinoceros
Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....

 and elephant
Elephant
Elephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...

) 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." Certain sub-Saharan Africa
Sub-Saharan Africa
Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara...

 countries have a 9.53 mm (0.375196850393701 in) minimum caliber rule for hunting the Big Five
Big Five game
The phrase Big Five game was coined by white hunters and refers to the five most difficult animals in Africa to hunt on foot. The term is still used in most tourist and wildlife guides that discuss African wildlife safaris. The collection consists of the lion, African elephant, cape buffalo,...

. It also cannot be used in countries which ban civilian use of former or current military rifle cartridges.

Initial development

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 (1.4580145801458E-06 gr), 0.338 inches (8.6 mm) diameter bullet at 914 m/s that could penetrate five layers of military body armour at 1000 m (1,094 yd) and still make the kill. After preliminary experiments, a .416 Rigby
.416 Rigby
The .416 Rigby or 10.6x74mm was designed in 1911 by John Rigby & Company of London, England as a dangerous game cartridge and is the first one to use a bullet with a diameter of .416"...

 case necked down to take a 0.338 inches (8.6 mm) bullet
Bullet
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...

 was selected, since this diameter presents an optimum of sectional density
Sectional density
Sectional density is the ratio of an object's mass to its cross-sectional area. It conveys how well an object's mass is distributed to overcome resistance. For illustration, a needle can penetrate a target medium with less force than a coin of the same mass...

 and penetrating capability
Penetration (weapons)
Strictly speaking penetration occurs when a projectile enters a target without passing through it and perforation occurs when the projectile completely passes through the target, but the word penetration is commonly used to refer to either....

 for practical spin stabilized rifle bullets (bullets up to about 5 to 5.5 calibers in length). The .416 Rigby is an English big game cartridge that was designed to accommodate 325 MPa (47,137 psi) pressures. One of the disadvantages of these old cartridge cases, which were intended for firing cordite
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...

 charges instead of modern smokeless powder
Smokeless powder
Smokeless powder is the name given to a number of propellants used in firearms and artillery which produce negligible smoke when fired, unlike the older gunpowder which they replaced...

, is the thickness of the sidewall just forward of the web. During ignition, the cartridge's base, forward to the bolt face, is not supported. The case is driven back against the bolt face which results in the stretching of the case, particularly the sidewall immediately forward of the web. When the sidewall resists the outward expansion against the chamber, the pressure stretches the case thereby increasing its length resulting in the sidewall becoming thinner at that stretch point.

During the process RAI employed Brass Extrusion Labs Ltd. (BELL) of Bensenville, Illinois, to make the .338/416 or 8.58×71mm cartridge cases, Hornady
Hornady
Hornady Manufacturing Company is an American manufacturer of ammunition and handloading components, based in Grand Island, Nebraska.The company was founded by Joyce Hornady in 1949 and is currently run by his son Steve Hornady who took over after his father's death in a plane crash in 1981.Hornady...

 produced bullets, and RAI built a sniper rifle under contract for the U.S. Navy. RAI found that the BELL cases did not fulfill the requirements. Pressed by military deadlines RAI looked for another case producer and contacted Lapua of Finland in 1984. RAI was forced to drop out of the program due to financial difficulties. Subsequently, Lapua of Finland put this cartridge into limited production. The .338/416 rifle program was later cancelled when the contractors were unable to make the cartridge meet the project's velocity target 16.2 gram at 914 m/s (250 gr at 3000 ft/s), due to weak brass cases.

Final development

The current .338 Lapua Magnum cartridge was developed as a joint venture between the UK rifle manufacturer Accuracy International
Accuracy International
Accuracy International is a specialist British firearms manufacturer based in Portsmouth, Hampshire, England and best known for producing the Accuracy International Arctic Warfare series of precision sniper rifles...

 and the Finnish ammunition manufacturer Lapua.

Lapua opted to redesign the .338/416 cartridge. In the new case design, particular attention was directed toward thickening and metallurgically strengthening the case's web and sidewall immediately forward of the web. In modern solid head cases, the hardness of the brass is the major factor that determines a case's pressure limit before undergoing plastic deformation. Lapua tackled this problem by creating a hardness distribution ranging from the head and web (hard) to the mouth (soft) as well as a strengthened (thicker) case web and sidewall immediately forward of the web. This resulted in a very pressure resistant case, allowing it to operate at high pressure and come within 15 m/s (50 ft/s) of the original velocity goal.
Lapua also designed a 16.2 gram (1.4580145801458E-06 gr) .338 calibre Lock Base B408 full metal jacket bullet
Full metal jacket bullet
A full metal jacket is a bullet consisting of a soft core encased in a shell of harder metal, such as gilding metal, cupronickel or less commonly a steel alloy. This shell can extend around all of the bullet, or often just the front and sides with the rear left as exposed lead...

, modeled after its .30 calibre Lock Base bullet configuration.
The result was the .338 Lapua Magnum cartridge which was registered with C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
The Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives is an international organisation whose members are 14 states, mainly European....

) in 1989. With the procurement by the Dutch Army, the cartridge became NATO codified.

The .338 Lapua Magnum is considered an ideal military long-range anti-personnel cartridge by long-range sniping specialists like John D. Taylor and Dean Michaelis. It fills the gap between weapons chambered for standard military rounds such as the 7.62x51mm NATO and large, weighty rifles firing the .50 BMG
.50 BMG
The .50 Browning Machine Gun or 12.7×99mm NATO is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s. Entering service officially in 1921, the round is based on a greatly scaled-up .30-06 cartridge...

 cartridge. It also offers a tolerable amount of barrel wear, which is important to military snipers who tend to fire thousands of rounds in practice every year to acquire and maintain expert long-range marksmanship.The Finnish Army found out during a test/trails program and 7 years of actual service that the barrels of their Sako TRG-42 sniper rifles lasted 7000 to 8000 rounds with Lapua Lock Base B408 factory ammunition before showing impermissible accuracy decay. The Finnish Army consistent accuracy requirement for these rifles is ≤ 1 MOA
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....

 at 1000 m. If this requirement is not met the TRG-42 gets a new barrel. This is normal practice for active high performance precision rifle operators who regard barrels as expendable items. The continuous use of very powerful handloads
Handloading
Handloading or reloading is the process of loading firearm cartridges or shotgun shells by assembling the individual components , rather than purchasing completely assembled, factory-loaded cartridges...

 (which results in higher muzzle velocities) resulted in much quicker throat erosion reducing the TRG-42 barrels accuracy life to 1500 to 2000 rounds.
Like every other big cartridge the .338 Lapua Magnum presents a stout recoil
Recoil
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gasses, according to Newton's third law...

. An appropriate fitting stock
Stock (firearm)
A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, to which the barrel and firing mechanism are attached, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a...

 and an effective muzzle brake
Muzzle brake
Muzzle brakes and recoil compensators are devices that are fitted to the muzzle of a firearm or cannon to redirect propellant gases with the effect of countering both recoil of the gun and unwanted rising of the barrel during rapid fire...

 will help to reduce recoil induced problems, enabling the operator to fire more rounds before getting too uncomfortable to shoot accurately. Good factory loads, multiple projectile weights and factory special application ammunition are all available.In 1990, the US military Adjutant General's Office issued a legal opinion holding that the Sierra MatchKing bullet (and similar bullets of other manufacturers), despite being a hollow point design, is not designed specifically to cause greater damage or suffering in a human target, and in fact normally does not create a wound readily distinguishable from wounds caused by conventional full metal jacket bullets, and is therefore in their opinion legal under the Hague Convention
Hague Conventions (1899 and 1907)
The Hague Conventions were two international treaties negotiated at international peace conferences at The Hague in the Netherlands: The First Hague Conference in 1899 and the Second Hague Conference in 1907...

 for use in war.


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. These (semi) custom bolt actions are used with other high grade rifle and sighting components to build custom sporting and target rifles.

Law enforcement and military users

The .338 Lapua Magnum cartridge is in law enforcement
Law enforcement agency
In North American English, a law enforcement agency is a government agency responsible for the enforcement of the laws.Outside North America, such organizations are called police services. In North America, some of these services are called police while others have other names In North American...

 or military
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 use with:: RENEA
RENEA
The Reparti i Neutralizimit të Elementit të Armatosur , commonly known by its acronym RENEA, is the main Albanian counter-terrorist and critical incident response unit. The force was constituted the early 1990s in response to the growing crime levels in the country after the fall of communism...

—Sako TRG-42: Accuracy International AWSM and Blaser Tactical 2
Blaser 93 Tactical
The Blaser LRS 2 and Blaser Tactical 2 are German sniper rifles, used by German and Dutch police forces as well as the Australian military and special police units. The rifles are manufactured by the German fire arms manufacturer Blaser. The LRS 2 and Tactical 2 rifles are straight-pull bolt-action...

: Canadian Forces
Canadian Forces
The Canadian Forces , officially the Canadian Armed Forces , are the unified armed forces of Canada, as constituted by the National Defence Act, which states: "The Canadian Forces are the armed forces of Her Majesty raised by Canada and consist of one Service called the Canadian Armed Forces."...

—C14 Timberwolf Medium Range Sniper Weapon System (MRSWS): TAP. : Military of Denmark
Military of Denmark
The armed forces of the Kingdom of Denmark, known as the Danish Defence is charged with the defence of the Kingdom of Denmark.The Chief of Defence is the head of the Danish Armed Forces, and is head of the Defence Command which is managed by the Ministry of Defence. Constitutionally, the...

—Sako TRG-42: Special forces and reconnaissance units of the Military of Estonia
Military of Estonia
The Estonian Defence Forces is the name of the unified armed forces of the Republic of Estonia. The Estonian military is a defence force consisting of Maavägi , Merevägi , Õhuvägi and a paramilitary organization Kaitseliit...

 (TRG-42).: Finnish Defence Forces
Finnish Defence Forces
The Finnish Defence Forces are responsible for the defence of Finland. It is a cadre army of 15,000, of which 8,900 are professional soldiers , extended with conscripts and reservists such that the standard readiness strength is 34,700 people in uniform...

8.6 TKIV 2000 = Sako TRG-42: Erma SR-100, AMP Technical Services DSR 1
AMP Technical Services DSR-1
The DSR-1 is a compact bolt-action rifle designed, manufactured and marketed by the German company DSR-Precision GmbH and was marketed also by the German company AMP Technical Services as a specialized sniper rifle for police sharpshooters...

, GOL Sniper Magnum
GOL Sniper Magnum
The GOL-Sniper Magnum is a bolt-action sniper rifle designed by the German company Gol-Matic GmbH of Birkenau, Hesse. The rifle is available in tactical as well as sporting and match configurations.-Design:...

: french Army , GIGN: Anti-Terrorist Unit EKAM
Special Anti-Terrorist Unit
The Special Suppressive Anti-Terrorist Unit is the Greek counter-terrorism unit of the Hellenic Police. It is the most distinguished part of the Hellenic Police...

—Sako TRG-41: Kopassus
Kopassus
Kopassus is an Indonesian Army special forces group that conducts special operations missions for the Indonesian government, such as direct action, unconventional warfare, sabotage, counter-insurgency, counter-terrorism, and intelligence gathering.Kopassus was founded on April 16, 1952...

Accuracy International AWSM
Accuracy International AWM
The AWM is a sniper rifle manufactured by Accuracy International. It is also known as the AWSM , which typically denotes the .338 Lapua Magnum version.-The Arctic Warfare Magnum system:...

: Irish Army
Irish Army
The Irish Army, officially named simply the Army is the main branch of the Defence Forces of Ireland. Approximately 8,500 men and women serve in the Irish Army, divided into three infantry Brigades...

Accuracy International AWM
Accuracy International AWM
The AWM is a sniper rifle manufactured by Accuracy International. It is also known as the AWSM , which typically denotes the .338 Lapua Magnum version.-The Arctic Warfare Magnum system:...

: H-S Precision Pro-Series 2000 HTR militarized semi-custom bolt-action rifle: Sako TRG-42: Pasukan Gerakan Khas
Pasukan Gerakan Khas
The Pasukan Gerakan Khas is an elite high-profile counter-terrorism and special operations tactical unit of the Royal Malaysia Police...

Accuracy International AWM
Accuracy International AWM
The AWM is a sniper rifle manufactured by Accuracy International. It is also known as the AWSM , which typically denotes the .338 Lapua Magnum version.-The Arctic Warfare Magnum system:...

: Dutch military—Accuracy International AWSM, Sako TRG-41: GROM
GROM
GROM is one of five special forces units of the Polish Armed Forces. It was officially activated on July 8, 1990...

—Accuracy International AWM-, 1 Pułk Specjalny Komandosów
1st Special Commando Regiment
The 1 Pułk Specjalny Komandosów, 1 PSK is one of the three special operations forces currently operating within the Polish military's structure, Special Forces of Poland....

: Military of Portugal - Accuracy International AWSM
Accuracy International AWM
The AWM is a sniper rifle manufactured by Accuracy International. It is also known as the AWSM , which typically denotes the .338 Lapua Magnum version.-The Arctic Warfare Magnum system:...

: Alpha Group
Alpha Group
The Alpha Group , is an elite component of Russia's Spetsnaz as well as the dedicated counter-terrorism unit of the Federal Security Service...

 and SOBR
SOBR
The Special Rapid Response Unit or SOBR is an elite commando unit of the Russian Interior Ministry, involved in anti-criminal operations....

—Accuracy International AWSM and Sako TRG-42: PGM 338: Military of Slovenia
Military of Slovenia
The Military of Slovenia consists of the Slovenian Armed Forces . The SAF are the armed forces of Slovenia. Since 2003, it is organized as a fully professional standing army...

—PGM 338: Sako TRG-42: Sako TRG-42: 350 TRG-42 rifles acquired., PGM 338: Sako TRG-42: British military—Accuracy International AWSM: United States Army
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

—M24A3 Sniper Weapon System

The .338 Lapua Magnum has been designated a "cartridge of interest" by the National Defense Industrial Association (NDIA). It is being groomed to replace the .300 Winchester Magnum
.300 Winchester Magnum
The .300 Winchester Magnum is a popular, belted, bottlenecked magnum rifle cartridge that was introduced by Winchester Repeating Arms Company in 1963 as a member of the family of Winchester Magnum cartridges. The .300 Winchester Magnum is a magnum cartridge designed to fit in a standard length...

 and the .50 BMG for anti-personnel long-range service in the U.S. military. On June 17, 2008, the U.S. government issued a market survey to support a requirement for a Precision Sniper Rifle (PRS) to possibly replace the currently fielded Bolt Action SOF Sniper Systems MK 13 (.300 Winchester Magnum) and the M40 and M24 (7.62×51mm NATO)) chambered to safely fire factory produced "non-wildcat" .338 caliber ammunition.

Cartridge dimensions

Extremely thick-walled brass results in a 7.40 ml
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...

 (114 grains
Grain (measure)
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...

 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 rifles, semi-automatic
Semi-automatic firearm
A semi-automatic, or self-loading firearm is a weapon which performs all steps necessary to prepare the weapon to fire again after firing—assuming cartridges remain in the weapon's feed device or magazine...

 and automatic firearm
Automatic firearm
An automatic firearm is a firearm that loads another round mechanically after the first round has been fired.The term can be used to refer to semi-automatic firearms, which fire one shot per single pull of the trigger , or fully automatic firearms, which will continue to load and fire ammunition...

s alike, under extreme conditions.
.338 Lapua Magnum maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 ≈ 20 degrees. The common rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

 twist rate for this cartridge is 254 mm (1 in 10 in), 6 grooves, Ø lands = 8.38 mm, Ø grooves = 8.58 mm, land width = 2.79 mm and the primer type
Percussion cap
The percussion cap, introduced around 1830, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather.Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the...

 is large rifle magnum.

According to the official C.I.P. decisions and tables edition 2007 the .338 Lapua Magnum case can handle up to 420 MPa (60,916 psi) piezo pressure. This now prevails over the C.I.P. decisions and tables edition 2003, that rated the .338 Lapua Magnum at 470 MPa (68,167 psi) maximum piezo pressure. Remarkably the 470 MPa (68,167 psi) maximum piezo pressure C.I.P. ruling for the .300 Lapua Magnum
.300 Lapua Magnum
The .300 Lapua Magnum is a specialized rimless bottlenecked centerfire cartridge developed for long-range rifles. The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the .300 Lapua Magnum, which is essentially a necked-down version of the .338 Lapua Magnum...

 cartridge, which is based on the same case, was not accordingly changed.
In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of the prevailing maximum C.I.P. pressure to certify for sale to consumers.

Lapua is ambivalent on the maximum piezo pressure of this cartridge.
In the article by Janne Pohjoispää Lapua propagates the C.I.P. 2006 ruling of 420 MPa (60,915 psi) maximum piezo pressure. To further complicate matters the mentioned 56,000 CUP
Copper units of pressure
Copper units of pressure or CUP, and the related lead units of pressure or LUP, are terms applied to pressure measurements used in the field of internal ballistics for the estimation of chamber pressures in firearms. These terms were adopted by convention to indicate that the pressure values were...

 C.I.P. copper crusher pressure in this article would translate in ≈ 447.5 MPa (64,903 psi) C.I.P. piezo pressure according to a study on the conversion from CUP to PSI for rifle cartridges by Denton Bramwell.
The C.I.P. 2003 ruling of 470 MPa (68,167 psi) piezo pressure is corroborated by Lapua Australia in the History and development of the .338 Lapua Magnum article by Alan C. Paulson.
A reverse engineering simulation with QuickLOAD
QuickLOAD
QuickLOAD is an internal ballistics predictor computer program for fire arms.For computations apart from other parameters* the cartridge* the used projectile * the gunbarrel length* the cartridge overall length* the used propellant...

 internal ballistic software predicted that Lapua load their factory .338 Lapua Magnum ammunition at ≈ 420 MPa (60,915 psi) piezo pressure as Alan C. Paulson asserts in his article.

The large boltface combined with the high maximum pressure makes that the .338 Lapua Magnum should only be chambered in rifles that are capable of handling such large and fierce cartridges and thus high bolt thrust
Bolt thrust
Bolt thrust or breech pressure is a term used in internal ballistics and firearms that describes the amount of rearward force exerted by the propellant gases on the bolt or breech of a firearm action or breech when a projectile is fired...

 safely. Chambering such powerful super magnum cartridges in rifles intended for normal magnum rifle cartridges and using high pressure loads can cause serious or fatal injury to the shooter and bystanders.

The American .338-378 Weatherby Magnum
.338-378 Weatherby Magnum
The .338-378 Weatherby Magnum started out as the wildcat cartridge, .338-378 Keith-Thomson Magnum during the early 1960s. Keith and Thomson are Elmer Keith and R.W. "Bob" Thomson. The 338-378 Keith-Thomson Magnum is slightly shorter than the .338-378 Weatherby Magnum. However this is only a neck...

 cartridge introduced in 1998 and the American .338 Remington Ultra Magnum
.338 Remington Ultra Magnum
The .338 Remington Ultra Magnum is a .338 caliber rifle cartridge introduced by Remington Arms in 2002. It is a beltless, rebated rim cartridge based on the .300 Remington Ultra Magnum case shortened .090" loaded with a .338 caliber bullet...

 (.338 RUM) cartridge introduced in 2000 are probably the closest currently (2007) commercially available ballistic twins of the .338 Lapua Magnum. The .338-378 Weatherby Magnum is however a belted
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...

 cartridge and the .338 Remington Ultra Magnum is a rebated rim
Rim (firearms)
A rim is an external flange that is machined, cast, molded, stamped or pressed around the bottom of a firearms cartridge. The rim may serve a number of purposes, the most common being as the place for the extractor to engage...

 cartridge.

Performance with standard cartridges

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, 1500 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 1500 m (1,640 yd) under warm summer conditions at a muzzle velocity of 915 m/s. However, to be able to maintain 80 to 90% hit probability on non-moving 45 by 90 cm (17.7 by 35.4 in) reactive army targets, this maximum shooting distance has to be reduced to 1300 metres (1,422 yd) at freezing point conditions or 1100 m (1,203 yd) in Arctic winter conditions, when the muzzle velocity may drop to 880 m/s (2,887 ft/s) - i.e. only during optimal warm summer conditions the 1500 m (1,640 yd) maximum shooting distance is realistically achievable.

Loaded with more aerodynamic very-low-drag bullet
Very-low-drag bullet
Very-low-drag bullets are primarily a small arms ballistics development of the 1980s–1990s, driven by shooters' desire for bullets that will give a higher degree of accuracy and kinetic efficiency, especially at extended ranges. To achieve this the projectile must minimize air resistance in flight...

s such as the traditionally lead cored 19.44 g (300.0 gr) Lapua Scenar GB528 VLD bullet (G1 BC
Ballistic coefficient
In ballistics, the ballistic coefficient of a body is a measure of its ability to overcome air resistance in flight. It is inversely proportional to the negative acceleration—a high number indicates a low negative acceleration. BC is a function of mass, diameter, and drag coefficient...

 = 0.736) or the Lost River Ballistics J40 .338 17.5 gram (270 gr) CNC manufactured mono-metal bullet (G1 BC = 0.871) the long-range performance and supersonic range of .338 Lapua Magnum rifles can be improved. These longer very-low-drag bullets require a 254 mm (1 in 10 inch) twist rate to stabilize them. Due to the lower practically possible muzzle velocities for a relative heavy bullet like the 19.44 g (300 gr) Lapua Scenar GB528 VLD bullet it gains about 104 m (114 yd) extra supersonic range under International Standard Atmosphere
International Standard Atmosphere
The International Standard Atmosphere is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes. It has been established to provide a common reference for temperature and pressure and consists of tables of...

 sea level conditions (air density ρ = 1.225 kg/m3) at a muzzle velocity of 837 m/s (2750 ft/s) when compared to the standard 16.2 g (250 gr) Lapua Scenar GB488 VLD at a muzzle velocity of 915 m/s (3002 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. The .338 17.5 gram (270 gr) Lost River Ballistic Technologies J40 match bullet made out of a copper nickel alloy is one of the most aerodynamic .338 calibre bullets available. It has a 1800 m (1969 yd) supersonic range under optimal warm summer conditions at a muzzle velocity of 869 m/s (2850 ft/s). This makes engaging static targets up to 1800 m (1969 yd) feasible.

Performance improvement experiments with non-standard cartridges

Improvement beyond this standard while still using standard .338 Lapua Magnum brass is possible, but the bullets have to be very long (over 5.5 calibers in length) and the normal cartridge overall length of 93.5 mm has to be exceeded. The common 254 mm (1:10 inch) rifling twist rate also has to be tightened to stabilize very long projectiles. Such commercially non-existent cartridges are termed "wildcats"
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...

. The use of a wildcat .338 Lapua Magnum based cartridge demands the use of a custom or customized rifle with an appropriately cut chamber and fast-twist bore. The firearm action
Firearm action
In firearms terminology, an action is the physical mechanism that manipulates cartridges and/or seals the breech. The term is also used to describe the method in which cartridges are loaded, locked, and extracted from the mechanism. Actions are generally categorized by the type of mechanism used...

 and if a repeating arm is required the magazine(s) must also be able to cope with dimensional increases.

An example of such a special .338 calibre extreme range bullet is the German CNC manufactured mono-metal 18.92 gram (292 gr) LM-105 (G1 BC ≈ 0.93 – this Ballistic coefficient (BC) is calculated by its designer, Mr. Lutz Möller, and not proven by Doppler radar
Doppler radar
A Doppler radar is a specialized radar that makes use of the Doppler effect to produce velocity data about objects at a distance. It does this by beaming a microwave signal towards a desired target and listening for its reflection, then analyzing how the frequency of the returned signal has been...

 measurements). If Mr. Möller's assumptions are correct, the LM-105 would have a supersonic range of ≈ 2,000 m (2,200 yd) at a muzzle velocity of 915 m/s (3,002 ft/s) under International Standard Atmosphere
International Standard Atmosphere
The International Standard Atmosphere is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes. It has been established to provide a common reference for temperature and pressure and consists of tables of...

 sea level conditions (air density ρ = 1.225 kg/m3). The 2010 version of the LM-105 bullet has an overall length of 54.3 mm (2.14 in) or 6.33 calibers and derives its exceptional low drag from a radical LD Haack or Sears-Haack
Sears-Haack body
The Sears–Haack body is the aerodynamic body shape with the lowest theoretical wave drag. Aircraft designed to operate at high subsonic or supersonic speeds have their cross-sectional areas designed to match as closely as possible the proportions of Sears-Haack body.By Whitcomb's area rule, the...

 profile in the bullet's nose area. Rifles chambered for this wildcat cartridge, with a cartridge overall length of 105 mm (4.13 in), and equipped with custom made 178 mm (1:7 inch) progressive twist rate 900 mm (35.43 in) long barrels with a 2° cone-angle (the standard C.I.P. cone-angle for the .338 Lapua Magnum is 6°) cone area finished first and second at several long range competitions. Its most recent win (2007) was in an international Special Forces
Special forces
Special forces, or special operations forces are terms used to describe elite military tactical teams trained to perform high-risk dangerous missions that conventional units cannot perform...

 and police
Police
The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

 sniper competition in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 against rifles chambered for 7.62x51mm NATO up to .50 BMG at ranges from 100 m – 1,500 m (109 yd – 1,640 yd). The LM-105 bullet exhibited its very low wind drift susceptibility notably at ranges beyond 800 m (875 yd). A real world average G1 BC of ≈ 0.90 to 0.93 is commonly adopted by the users of this bullet, for making long range trajectory predictions using ballistics calculators.

The .343 Lapua Magnum LM-107 was a wildcat cartridge under development based on the standard .338 Lapua Magnum cartridge case. The LM-107 was hoped to boost the ballistic performance of the LM-105 by achieving an increase in supersonic range. The 19.3 g (298 gr) LM-107 projectile design is 59 mm long and has a Haack profiled nose and an Adams profiled tail. The rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

 twist rate for the .343 Lapua Magnum LM-107 wildcat cartridge was chosen at 180 mm (1:7 inch), Ø lands = 8.72 mm, Ø grooves = 8.45 mm and loaded with the LM-107 projectile has a cartridge overall length of 107 mm. The length of the neck is increased from 8,31 to 8,50 mm to support the bigger LM-107 bullet. Several other dimensions of the .338 Lapua Magnum parental cartridge are also changed. The shoulder angle gets steepened from 40° to 60° and the body taper is set at 1°. The throat area is set at a 2° cone-angle. All this modifications make the .343 Lapua Magnum a fairly comprehensively revised wildcat cartridge. Out of a 900 mm (35.43 in) long progressive twist barrel Mr. Möller expected to achieve 909 m/s (2,982 ft/s) muzzle velocity. If Mr. Möller's design assumptions are correct the LM-107 projectile with a calculated G1 BC of 1.02 will offer a supersonic range of ≈ 2,170 m (2,373 yd) at a muzzle velocity of 909 m/s (2,982 ft/s) under International Standard Atmosphere
International Standard Atmosphere
The International Standard Atmosphere is an atmospheric model of how the pressure, temperature, density, and viscosity of the Earth's atmosphere change over a wide range of altitudes. It has been established to provide a common reference for temperature and pressure and consists of tables of...

 sea level conditions (air density ρ = 1.225 kg/m3). However, the LM-107 project never materialized so there is no practical evidence to support these assumptions by Mr. Moller.

The .300 Lapua Magnum

The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the .300 Lapua Magnum
.300 Lapua Magnum
The .300 Lapua Magnum is a specialized rimless bottlenecked centerfire cartridge developed for long-range rifles. The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the .300 Lapua Magnum, which is essentially a necked-down version of the .338 Lapua Magnum...

, which is essentially a necked-down version of the .338 Lapua Magnum. The .338 cartridge case was used for this since it has the capability to operate with high chamber pressures which, combined with smaller and hence lighter bullet
Bullet
A bullet is a projectile propelled by a firearm, sling, or air gun. Bullets do not normally contain explosives, but damage the intended target by impact and penetration...

s result in very high muzzle velocities.

The Finnish ammunition manufacturer Lapua got the .300 Lapua Magnum C.I.P. certified, so it became an officially registered and sanctioned member of the Finnish "family" of super magnum rifle cartridges. The .300 Lapua Magnum is not commercially available and currently exists only as a C.I.P. datasheet. 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.

The .300 Lapua Magnum has a 7.33 ml
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...

 (113 grains
Grain (measure)
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...

 H2O) cartridge case capacity.



.300 Lapua Magnum maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 ≈ 25 degrees. The common rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

 twist rate for this cartridge is 240 mm (1 in 9.45 in), 4 grooves, Ø lands = 7.62 mm, Ø grooves = 7.82 mm, land width = 4.47 mm and the primer type
Percussion cap
The percussion cap, introduced around 1830, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather.Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the...

 is large rifle magnum.

According to the official C.I.P. guidelines the .300 Lapua Magnum case can handle up to 470 MPa (68,167 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

This for rifles very high maximum allowed chamber pressure level indicates that the cases of the .300 and .338 Lapua Magnum are built extremely sturdy to cope with this for rifles very high operating pressure. The large boltface combined with the high 470 MPa (68,000 PSI) maximum pressure makes that the .300 Lapua Magnum should only be chambered in rifles that are capable of handling such large and fierce cartridges and thus high bolt thrust safely. Chambering such powerful super magnum cartridges in rifles intended for normal magnum rifle cartridges and using 470 MPa (68,000 PSI) loads can cause serious or fatal injury to the shooter and bystanders.

The 7.62 UKM

The .338 Lapua Magnum cartridge is also used as the parent case for the German designed 7.62 UKM
7.62 UKM
The 7.62 UKM is a specialized rimless bottlenecked centerfire cartridge developed for long-range rifles. The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the 7.62 UKM, which is essentially a necked-down shortened version of the .338 Lapua Magnum...

, which is essentially a necked-down shortened version of the .338 Lapua Magnum. The use of the .338 cartridge case with its capability to operate at high chamber pressures resulted in magnum case capable of producing high muzzle velocities.

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. The 7.62 UKM is not commercially available and currently exists only as a C.I.P. datasheet. 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.

The 7.62 UKM has a 5.84 ml
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...

 (90 grains
Grain (measure)
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...

 H2O) cartridge case capacity.



7.62 UKM maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

Americans would define the shoulder angle at alpha/2 ≈ 20 degrees. The common rifling
Rifling
Rifling is the process of making helical grooves in the barrel of a gun or firearm, which imparts a spin to a projectile around its long axis...

 twist rate for this cartridge is 254 mm (1 in 10 in), 6 grooves, Ø lands = 7.62 mm, Ø grooves = 7.82 mm, land width = 2.79 mm and the primer type
Percussion cap
The percussion cap, introduced around 1830, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather.Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the...

 is large rifle magnum.

According to the official C.I.P. guidelines, the 7.62 UKM case can handle up to 470 MPa (68,000 psi) piezo pressure. In C.I.P.-regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.

Wildcats

The .338 Lapua Magnum case is also used as the parent case for a host of modified variants that are not officially registered with or sanctioned by C.I.P. or its American equivalent, SAAMI
Saami
Saami or SAAMI can stand for:*Sami people*Sami languages*Sporting Arms and Ammunition Manufacturers' Institute...

. Such cartridges which use commercial factory cases are generally known as wildcats
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...

. By changing the shape of standard factory cases (decreasing case taper and/or changing the shoulder geometry) the wildcatter generally increases the case capacity of the factory parent cartridge case, allowing more propellant to be used to generate higher velocities. Besides changing the shape and internal volume of the parent cartridge case, wildcatters also can change the original calibre. A reason to change the original calibre can be to comply with a minimal permitted calibre or bullet weight for the legal hunting of certain species of game. 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. With the .338 Lapua Magnum as the parent case wildcatters have created 7 mm (7 mm Katzmeier, 7 mm Fatso), .30 (.30-338 Lapua (Triebel), .30 Wolf), 8 mm (8 mm-338 Lapua (Triebel), LM-101), .338 (.338 Yogi, LM-105), .343 (.343 Lapua Magnum LM-107), 9.3 mm (9,3-338 Lapua Magnum (Triebel)), .375 (9.5x70 ELR) and .50 calibre (.510 Whisper
.510 Whisper
The .510 Whisper was developed by SSK Industries to shoot .510 bullets in a suppressed rifle. The case is based on the .338 Lapua Magnum cut down to . Neck wall thickness is reduced to and a small shoulder is cut into the body for head spacing...

) variants. The current (2008) benchrest
Benchrest shooting
Benchrest shooting is a sport in which very accurate and precise rifles are shot at paper targets from a rest or bench from a sitting position. Benchrest shooters are notoriously detail-oriented and constantly trying to further the accuracy potential of the rifle through experimentation. Nearly...

 1000 yards (914.4 m) 5-shot group world record holder 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 inches (3.56 cm) diameter 5-shot group on 7 July 2007.

See also

  • List of firearms
  • List of sniper rifles
  • List of rifle cartridges
  • 8 mm caliber
    8 mm caliber
    This article lists firearm cartridges which have a bullet in the to caliber range.*Length refers to the empty cartridge case length.*OAL refers to the overall length of the loaded cartridge.All measurements are in mm .-Pistol cartridges:...

  • 6.5x47mm Lapua
    6.5x47mm Lapua
    6.5x47mm Lapua is a rifle cartridge that was developed specifically for 300m competition by ammunition maker Nammo Lapua and the Swiss rifle manufacturer Grünig & Elmiger AG in 2005.-Features:The cartridge has many special features including: :...

  • 7.62 UKM
    7.62 UKM
    The 7.62 UKM is a specialized rimless bottlenecked centerfire cartridge developed for long-range rifles. The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the 7.62 UKM, which is essentially a necked-down shortened version of the .338 Lapua Magnum...

  • .300 Lapua Magnum
    .300 Lapua Magnum
    The .300 Lapua Magnum is a specialized rimless bottlenecked centerfire cartridge developed for long-range rifles. The commercially successful .338 Lapua Magnum cartridge has functioned as the parent case for the .300 Lapua Magnum, which is essentially a necked-down version of the .338 Lapua Magnum...

  • .338 Norma Magnum
    .338 Norma Magnum
    The .338 Norma Magnum is a cartridge first introduced in 2008 and coming into production in 2009. It is designed by the Swedish ammunition company Norma which is part of the Swiss RUAG group.-Design history:...


External links

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