.300 Lapua Magnum
Encyclopedia
The .300 Lapua Magnum is a specialized rimless
bottlenecked centerfire cartridge
developed for long-range rifle
s. 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. 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
s result in very high muzzle velocities.
manufacturer Lapua
got the .300 Lapua Magnum C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives
) certified, so it became an officially registered and sanctioned member of the Finnish 70 mm "family" of super magnum rifle cartridges. The .300 Lapua Magnum is not commercially available anymore today and currently (2007) 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.
(113 grains
H2O) cartridge case capacity. The exterior shape of the Lapua Magnum case was designed to promote reliable case feeding and extraction in bolt action rifles, semi-automatic
and automatic firearm
s alike, under extreme conditions.
.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
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
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 is a very high maximum allowed chamber pressure level and indicates that the cases of the .300 and .338 Lapua Magnum are built extremely sturdy. The large boltface combined with the high 470 MPa 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 loads can cause serious or fatal injury to the shooter and bystanders. A bolt-action
rifle
that theoretically could safely be chambered for the 94.5 mm long .300 Lapua Magnum is the Sako
TRG-42. This rifle was specially designed for .338 Lapua Magnum cartridges and can handle cartridges up to 95 mm overall length.
sniper
s, who tend to fire a lot of rounds in practice to acquire and maintain expert long-range marksmanship.
The Lapua/VihtaVuori international reloading guide 2008 reveals that at 690 mm (27.165 in) barrel length the .300 Lapua Magnum loaded with heavy .30 calibre bullets yields less muzzle energy compared to its .338 Lapua Magnum parent cartridge.
The American .30-378 Weatherby Magnum
cartridge introduced in 1996 and the American .300 Remington Ultra Magnum
(.300 RUM) cartridge introduced in 1999 are probably the closest currently (2007) commercially available ballistic twins of the .300 Lapua Magnum. The .30-378 Weatherby Magnum is however a belted
cartridge and the .300 Remington Ultra Magnum is a rebated rim
cartridge.
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...
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 long-range rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
s. 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. 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.
History
The Finnish ammunitionAmmunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...
manufacturer Lapua
Lapua
Lapua is a town and municipality of Finland.It is located next to the Lapua River in the province of Western Finland and is part of the Southern Ostrobothnia region. The town has a population of and covers an area of ofwhich is water...
got the .300 Lapua Magnum 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....
) certified, so it became an officially registered and sanctioned member of the Finnish 70 mm "family" of super magnum rifle cartridges. The .300 Lapua Magnum is not commercially available anymore today and currently (2007) 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
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...
it with .30 calibre bullets.
Cartridge dimensions
The .300 Lapua Magnum has 7.34 mlLitre
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. The exterior shape of the Lapua Magnum case was designed to promote reliable case 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.
.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 is a very high maximum allowed chamber pressure level and indicates that the cases of the .300 and .338 Lapua Magnum are built extremely sturdy. The large boltface combined with the high 470 MPa 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
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 470 MPa loads can cause serious or fatal injury to the shooter and bystanders. A bolt-action
Bolt-action
Bolt action is a type of firearm action in which the weapon's bolt is operated manually by the opening and closing of the breech with a small handle, most commonly placed on the right-hand side of the weapon...
rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...
that theoretically could safely be chambered for the 94.5 mm long .300 Lapua Magnum is the Sako
SAKO
SAKO, Limited is a Finnish firearm manufacturer located in Riihimäki....
TRG-42. This rifle was specially designed for .338 Lapua Magnum cartridges and can handle cartridges up to 95 mm overall length.
Additional information
The .300 Lapua Magnum’s main appeal is long-range shooting. Due to the large case capacity in relation to the 7.62 mm (.308 inch) calibre bore size the .300 Lapua Magnum is very harsh on barrels. The .300 Lapua Magnum typically wears out a rifle barrel in 1000 to 1500 rounds. A lot of thorough barrel cleaning (after every 5 to 10 shots) and carefully avoiding long strings of shots help to minimize barrel wear. This makes this cartridge unpractical for most competition and professional long-range shooters, like militaryMilitary
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...
sniper
Sniper
A sniper is a marksman who shoots targets from concealed positions or distances exceeding the capabilities of regular personnel. Snipers typically have specialized training and distinct high-precision rifles....
s, who tend to fire a lot of rounds in practice to acquire and maintain expert long-range marksmanship.
The Lapua/VihtaVuori international reloading guide 2008 reveals that at 690 mm (27.165 in) barrel length the .300 Lapua Magnum loaded with heavy .30 calibre bullets yields less muzzle energy compared to its .338 Lapua Magnum parent cartridge.
The American .30-378 Weatherby Magnum
.30-378 Weatherby Magnum
The .30-378 Weatherby Magnum is a cartridge introduced by Weatherby in 1996 that uses the same case as the previously existing .378 Weatherby Magnum and .460 Weatherby Magnum, necked down to a 30 caliber bullet. It is offered with bullets between 165 and 200 grains in factory loading, generating...
cartridge introduced in 1996 and the American .300 Remington Ultra Magnum
.300 Remington Ultra Magnum
The .300 Remington Ultra Magnum, also known as the .300 Ultra Mag or .300 RUM is a 7.62 mm caliber rifle cartridge , 7.62x72mm, or .30 caliber rifle cartridge introduced by Remington Arms in 1999. The .300 Remington Ultra Magnum is one of the largest commercially available .30 caliber magnums...
(.300 RUM) cartridge introduced in 1999 are probably the closest currently (2007) commercially available ballistic twins of the .300 Lapua Magnum. The .30-378 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 .300 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.
See also
- List of rifle cartridges
- 7 mm caliber7 mm caliberThis article lists firearm cartridges which have a bullet in the to caliber range.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge....
- 7.62 UKM7.62 UKMThe 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...
- .338 Lapua Magnum
External links and sources
- Reloading data for the .300 Lapua Magnum cartridge
- QuickLOADQuickLOADQuickLOAD 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 ballistics predictor computer program for fire arms - VihtaVuori Reloading Guide, 2002
- Lutz Möller's .300 Lapua Magnum Page with a computer made image of the cartridge - SOME LOAD SUGGESTIONS EXCEED THE C.I.P. LIMIT (4700 bar)