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==External links and sources==
==External links and sources==
* [http://www.lapua.com Lapua official site]
* [http://www.lapua.com Lapua official site]
* [http://www.caina-longbranch.com official site]
* [http://www.lapua.com/uploads/media/338LapuaMagnum2009.pdf Lapua product brochure .338 Lapua Magnum ammunition]
* [http://www.lapua.com/uploads/media/338LapuaMagnum2009.pdf Lapua product brochure .338 Lapua Magnum ammunition]
* [http://world.guns.ru/sniper/sn00-e.htm Modern Firearms List of Sniper Rifles]
* [http://world.guns.ru/sniper/sn00-e.htm Modern Firearms List of Sniper Rifles]

Revision as of 21:17, 20 April 2011

.338 Lapua Magnum
.338 Lapua Magnum cartridge
TypeRifle
Place of origin Finland
Service history
Used byMultiple official and civil users
WarsAfghanistan War, Iraq War
Production history
DesignerLapua
Designed1989
Produced1989–present
Specifications
Parent case.416 Rigby, .338/416
Case typeRimless, bottleneck
Bullet diameter8.58 mm (0.338 in)
Neck diameter9.46 mm (0.372 in)
Shoulder diameter13.82 mm (0.544 in)
Base diameter14.91 mm (0.587 in)
Rim diameter14.93 mm (0.588 in)
Rim thickness1.52 mm (0.060 in)
Case length69.20 mm (2.724 in)
Overall length93.50 mm (3.681 in)
Case capacity7.40 cm3 (114.2 gr H2O)
Rifling twist254 mm (1-10")
Primer typeLarge rifle magnum
Maximum pressure420.00 MPa (60,916 psi)
Ballistic performance
Bullet mass/type Velocity Energy
12.96 g (200 gr) SP 1,019 m/s (3,340 ft/s) 6,734 J (4,967 ft⋅lbf)
16.20 g (250 gr) Partition 897 m/s (2,940 ft/s) 6,516 J (4,806 ft⋅lbf)
16.20 g (250 gr) Lapua Scenar GB488 VLD 910 m/s (3,000 ft/s) 6,634 J (4,893 ft⋅lbf)
19.44 g (300 gr) Sierra HPBT MatchKing 826 m/s (2,710 ft/s) 6,632 J (4,892 ft⋅lbf)
19.44 g (300 gr) Lapua Scenar GB528 VLD 837 m/s (2,750 ft/s) 6,810 J (5,020 ft⋅lbf)
Test barrel length: 660 mm (26.0 inches)
Source(s): Accurate Powder[1] Lapua (690 mm; 27.2 inches) barrel)[2][3]

The .338 Lapua Magnum (8.6x70mm or 8.58x70mm) is a specialized rimless bottlenecked centerfire cartridge developed for military long-range sniper rifles. The Afghanistan War 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 round; however, its anti-materiel potential is limited, due to the bullet's lower kinetic energy compared with that of the .50 BMG's 35.64-to-55.08-gram (550.0 to 850.0 gr) projectiles. The loaded cartridge is 14.93 mm (0.588 in) in diameter (rim) and 93.5 mm (3.68 in) long. It can penetrate better-than-standard military body armour at ranges up to 1,000 metres (1,094 yd) and has a maximum effective range of about 1,750 metres (1,910 yd). Muzzle velocity is dependent on load and powder temperature and varies from 880 to 915 m/s (2,890 to 3,000 ft/s) for commercial loads with 16.2-gram (250 gr) bullets, which results in about 6,525 J (4,813 ft⋅lbf) of muzzle energy.

Non-C.I.P. conforming British military issue overpressure .338 Lapua Magnum cartridges with a 91.4 mm (3.60 in) overall length, loaded with 16.2-gram (250 gr) LockBase B408 very-low-drag bullets 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).[4][5][6][7][8][9]

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, 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."[10] Certain sub-Saharan Africa countries have a 9.53 mm (0.375 in) minimum caliber rule for hunting the Big Five. It also cannot be used in countries which ban civilian use of former or current military rifle cartridges.

History

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 (250 gr), 0.338-inch (8.6 mm) diameter bullet at 914 metres per second (3,000 ft/s) that could penetrate five layers of military body armour at 1,000 m (1,094 yd) and still make the kill. After preliminary experiments, a .416 Rigby case necked down to take a 0.338-inch (8.6 mm) bullet was selected, since this diameter presents an optimum of sectional density and penetrating capability for practical spin stabilized rifle bullets (bullets up to about 5 to 5.5 calibers in length).[11] 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 charges instead of modern smokeless powder, 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 8.58x71mm cartridge cases, 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.[12] RAI was forced to drop out of the program due to financial difficulties. Subsequently, Lapua of Finland put this cartridge into limited production.[13] 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

From its American origins, the current .338 Lapua Magnum cartridge was developed as a joint venture between the rifle building company Accuracy International and the Finnish ammunition manufacturer Lapua (including personal communication with Malcolm Cooper, the now-deceased founder of Accuracy International). In some contrast to this, Lapua states on its website that it developed the cartridge and mentions Mr. Cooper's Accuracy International as a cooperation partner.[14] Since Mr. Cooper cannot comment on this matter it cannot be resolved.

Lapua opted to elaborately 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 (250 gr) .338 calibre Lock Base B408 full metal jacket bullet, 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) 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 cartridge.[15] 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.[16] Like every other big cartridge the .338 Lapua Magnum presents a stout recoil. An appropriate fitting stock and an effective muzzle brake 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.[17][18]

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.

.338 Lapua Magnum-"Generation II"

338 Lapua Magnum Generation II is an ongoing development program initiated by Caina Longbranch in Canada since 1993 [19]based on the premise that while the foundations of this caliber are sound, the cartridge has not been exploited to its full potential which is considered to be 2000 meters in a combination of both accuracy and penetration. For the first time the 338 Lapua Magnum would truly represent maximum effective range in a Magnum sniping/hunting rifle configuration of a practical field weight.

Optimal potential while using the standard 338 Lapua cartridge case is achieved by seating the optimal projectile out to the longest practical length regardless of rifle action size. The foundation of ballistic engineering dictates that the projectile is the prima nuitant and that both the cartridge and the firearm, being only a “delivery system”, must be designed and built around accurately delivering the optimal projectile to the longest effective range rather than what can be fit in an existing action originally intended for another caliber. Shoving a projectile back in the cartridge case to fit an existing action is considered not only to be remarkably inefficient but creates needlessly high chamber pressures and is fundamentally flawed as “backwards engineering”in reducing the potential of this cartridge.

To accomplish this basic premise the optimal projectile at the time being the 300-grain Sierra Match King with a BC of .768 was seated out to the optimal length (OAL cartridge length: 3.98 inches + or - .01) so that the beginning of the projectile boat tail coincides with the case neck junction of the cartridge case. In doing this, maximum case capacity is maintained for extreme range while also having full projectile and cartridge case-mouth retention.

Recently, since 2007, better projectiles have been developed and are in the process of being finalized with ballistic tips while maintaining the optimal 300-grain weight but with significantly higher ballistic coefficients.

Achieving extreme range accurately with this cartridge is a combination of projectile, barrel and propellant development for an overall package or program. New projectiles beyond the Sierra are anticipated to have a seated cartridge length of 4.18 or 4.2 inches. With the Sierra projectile the optimal barrel twist was recorded in testing at 1:10 twist however subsequent testing by shooters and barrel makers through out the community determined the Sierra’s “sweet spot” is around 1:9.3 twist. With the new projectile’s longer length it’s anticipated the twist required to stabilize these projectiles of the same weight will be in the neighborhood of 1:9 or 1:8.5, necessitating rifling such as the proven 5-R rifling to reduce drag and increase barrel life.

At the same time, propellant is under development to achieve these extreme ranges of 2000 meters and beyond. It is anticipated that the successful propellant will be one that produces a pressure plateau rather than a pressure curve through out its burn time coupled with propellant grains that may be engineered with increased surface area. The development continues.

Law enforcement and military users

The .338 Lapua Magnum cartridge is in law enforcement or military[20][21] use with:

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 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.[28][29]

Cartridge dimensions

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 rifles, semi-automatic and automatic firearms 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 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 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 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[30] 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 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.[31] 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.[32] A reverse engineering simulation with QuickLOAD 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 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 cartridge introduced in 1998 and the American .338 Remington Ultra Magnum (.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 cartridge and the .338 Remington Ultra Magnum is a rebated rim cartridge.

Ballistic performance of the .338 Lapua Magnum

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, 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). However, to be able to maintain 80 to 90% hit probability on non-moving 45 cm × 90 cm (17.7 in × 35.4 in) reactive army targets, this maximum shooting distance has to be reduced to 1,300 metres (1,422 yd) at freezing point conditions or 1,100 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 1,500 m (1,640 yd) maximum shooting distance is realistically achievable.

Loaded with more aerodynamic very-low-drag bullets such as the traditionally lead cored 19.44 g (300.0 gr) Lapua Scenar GB528 VLD bullet (G1 BC ≈ 0.785) 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 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 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 and the normal cartridge overall length of 93.5 mm has to be exceeded. The common 250 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". 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 a fast-twist bore.

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 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 sea level conditions (air density ρ = 1.225 kg/m3). The LM-105 bullet has an overall length of 54.79 mm (2.157 in) and derives its exceptional low drag from a radical LD Haack or Sears-Haack 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 180 mm (1:7 inch) progressive twist rate[33] 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 and police sniper competition in Switzerland against rifles chambered for 7.62x51 mm 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).[34] 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.[35]

The .343 Lapua Magnum LM-107 was a wildcat cartridge under development based on the standard .338 Lapua Magnum cartridge case.[36] 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 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 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.

.338 Lapua Magnum as a parent case

The .300 Lapua Magnum

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 bullets 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 (113 grains 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 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 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, which is essentially a necked-down shortened version of the .338 Lapua Magnum.[37] 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 (90 grains 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 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 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

From left to right: cross sectioned and normal .338 Yogi cartridge cases compared to a factory .338 Lapua Magnum case.

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. Such cartridges which use commercial factory cases are generally known as wildcats. By blowing out standard factory cases the wildcatter generally hopes to gain extra muzzle velocity by increasing the case capacity of the factory parent cartridge case by a few percent. Practically there can be some muzzle velocity gained by this method, but the measured results between parent cartridges and their 'improved' wildcat offspring are often marginal. 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[38]), .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[36]), 9.3 mm (9,3-338 Lapua Magnum (Triebel)), .375 (9.5x70 ELR) and .50 calibre (.510 Whisper) variants. The current (2008) benchrest 1,000-yard (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-inch (35.64 mm) diameter 5-shot group on 7 July 2007.[39]

See also

References

  1. ^ .338 Lapua at Accurate Online.
  2. ^ Lapua product brochure .338 Lapua Magnum ammunition.
  3. ^ VihtaVuori international reloading guide 2009.
  4. ^ Freeze, Colin (May 4, 2010). "British sniper shoots down Canada’s bragging rights". The Globe and Mail. Accessed May 13, 2010.
  5. ^ Sheridan, Michael (May 3, 2010). British sniper Craig Harrison (The Silent Assassin) breaks record, kills target from 1.5 miles away". Daily News (New York). Accessed May 13, 2010.
  6. ^ Smith, Michael (May 2, 2010). "Hotshot sniper in one-and-a-half mile double kill". The Sunday Times (London). Accessed May 13, 2010.
  7. ^ Chandler, Neil (May 2, 2010). "SNIPER'S TALIBAN SHOTS EARN HIM PLACE IN MILITARY RECORD BOOKS". Daily Star (United Kingdom). Accessed May 13, 2010.
  8. ^ Alpert, Lukas I. (May 2, 2010). "Sniper kills Qaeda-from 1½ mi. away". New York Post. Accessed May 13, 2010.
  9. ^ Drury, Ian (May 2, 2010). "The super sniper: Hero picks off two Taliban from a mile and a half away". Daily Mail (United Kingdom). Accessed May 13, 2010.
  10. ^ Robertson, K: The Perfect Shot, Safari Press, Inc, Long Beach, 1999:p. 50.
  11. ^ What is the Maximum Length of a spin stabilized Projectile? by Mr. Beat Kneubühl.
  12. ^ Nammo Lapua Oy company website.
  13. ^ Barnes, Frank C., Cartridges of the World 8th Edition, Edited by M.L. McPherson, DBI Books, 1997, ISBN 0-87349-178-5.
  14. ^ "From an American dream to a Finnish success story". Archived from the original on 2009-05-18. Retrieved 2009-05-16. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  15. ^ Cartridges for Long-Range Sniping Rifles by Anthony G Williams
  16. ^ 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 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 (which results in higher muzzle velocities) resulted in much quicker throat erosion reducing the TRG-42 barrels accuracy life to 1500 to 2000 rounds.
  17. ^ 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 for use in war.
  18. ^ Sniper Use of Open-Tip Ammunition.
  19. ^ 39
  20. ^ worldrifles.com.
  21. ^ World Small Arms Inventory.
  22. ^ Australian Government Contract Notice View - CN68887 BLASER SNIPER RIFLES.
  23. ^ Australian Government Contract Notice View - CN152254 .338 BLASER ITEMS - VARIOUS.
  24. ^ "IDF Sniper Weapon System (SWS) .338 Lapua Magnum Bolt-Action Sniper Rifle". Archived from the original on 2009-05-18. Retrieved 2009-05-16. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  25. ^ H-S Precision Pro-Series 2000 HTR (Heavy Tactical Rifle).
  26. ^ Protecting the Holy Land by Charles Karwan
  27. ^ Waffen HQ Russian Infantry weapons.
  28. ^ US Special Operations Considers A ".338" Sniper Rifle.
  29. ^ Precession Sniper Rifle - Solicitation Number: H92222-09-PSR.
  30. ^ From an American dream to a Finnish success story.
  31. ^ Correlating PSI and CUP, a study done that shows a high correlation between CUP and PSI for rifle cartridges by Denton Bramwell.
  32. ^ History and development of the .338 Lapua Magnum.
  33. ^ Progressive twist rate barrels.
  34. ^ LM-105 "Dominator"
  35. ^ LM-105 Langstreckengeschoß geringer Winddrift (German)
  36. ^ a b LM-107 .343 Lapua Magnum
  37. ^ The 7.62 UKM. A German 300 Magnum Wildcat Extraordinary.
  38. ^ The 7mm Fatso - The Ultimate Short Magnum! by Greg Duley.
  39. ^ Sarver Shoots 1.403″ Group at 1000 Yards.

19 Caina Longbranch developmental information & official website

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