Target Sports

SPORTS STARS: THE .338 LAPUA MAGNUM PART ONE

Created on 29th May 2009

With mod range safety rules hot news, let's look at the cartridge that caused the Army to review muzzle energies - the .338 Lapua Magnum (8.6 x 70mm). The cartridge is used by British Army snipers and has excessive reach for most MoD smallarms ranges.

0.33" cartridges were introduced in the USA and Britain (colonial sporting and expatriate markets) early last century. Bullet diameters have varied from 0.330" to 0.338". While African sporting use declined post-WW2, the North American market took off with .338 Magnums introduced by A-Square, Dakota, Lazzeroni, Remington, Winchester and Weatherby, and most recently (in 2006) the .338 Federal, a deer number based on the .308W case.

Kilometre

Ultra-long-range sniping started on a ‘private venture basis' late in the Vietnam War, to counter VietCong guerrillas who operated openly just beyond effective 7.62mm range outside US bases. However, the first such factory rifles were all 0.5" anti-materiel designs, intended to engage vehicles and parked aircraft at up to 2,000m range.

With the incidence of infantry taking fire from heavy weapons at 1km range becoming common (even with relatively lightly armed opponents, as with the current conflict in Afghanistan), the need for a sniper cartridge with considerably greater reach than the 7.62mm's 600-800m began to emerge. The .300 Winchester Magnum extended effective range to the 1,000m mark, but gave short barrel life, and the military are leery of belted cases. Another requirement emerged in the 1980s as body armour was developed - penetrating this at extended ranges needed high retained energy values.

The US Navy (yes - the Navy!) commissioned Research Armament Industries (RAI) to produce answers in 1983. This outfit identified the .338" calibre as offering optimum long-range ballistics - a 250gn bullet at 3,000fps MV was needed to meet the sponsor's range and penetration requirements. The old British .416 Rigby elephant cartridge's case was chosen in necked-down and shortened form. This gave a huge case, with over double the capacity of .308 Winchester and nearly 25% more than the .300 Winchester Magnum. However, the project died, largely because RAI ran into strength problems with the case and couldn't meet the performance targets. Also, US forces adopted the Barratt ‘Light-Fifty' at this time. A subsequent enthusiasm for half-inch calibre took hold, with governments and manufacturers worldwide jumping onto this bandwagon.

Lapua

However, the size, weight, and recoil of .50BMG rifles make them distinctly foot soldier-unfriendly and muzzle blast, flash and dust signatures are unacceptable to anti-personnel sniper teams, who need to stay concealed for long periods taking on targets of opportunity. The Finns saw a market in filling the 7.62-.50BMG performance gap, and the basic work had already been done. With Accuracy International co-operating on the rifle, Lapua developed the Rigby case to accept the pressures needed to give a 0.339" diameter B408 FMJBT Lock-Base bullet 2,950fps MV in any climactic conditions from a 695mm (27.4") barrel. CIP MAP, using the Piezo pressure measuring system, is 470 MPa (68,150psi) within a range that can legitimately exceed 70,000psi (which sees rifles proof-tested at around 90,000psi!). Introduced in 1987, only Lapua and Norma make cases or ammunition. Neither are cheap, with unprimed Lapua cases costing £1.75 each and factory cartridges £4. Performance is more than adequate for the long-range sniper, with bullets remaining supersonic to beyond 1,300m. Nammo Lapua claims its number is effective to 1,500m - over 9/10 of a mile - but this obviously depends on conditions, user-skill, the rifle and its scope. Barrel life is an excellent 4,000 to 5,000 rounds, important in such rifles, as military snipers practise constantly to keep their shooting skills honed.

Rifles and countries

With a COL of 3.681" (93.5mm), this cartridge needs a very long-throw action. Moreover, the high pressures allied to the huge 0.588" (14.93mm) diameter case-head produce exceptional bolt-thrust, requiring equally strong actions. Despite this, the typical .338 military rifle weighs around 15lb (6.75Kg) ‘bare', only slightly heavier than 7.62mm versions and under half that of most .50BMG rifles. AI developed its AWSM (Arctic Warfare Super Magnum) for this cartridge, and Sako followed with the same-concept TRG-41 (uprated to TRG-42 when adopted by the Finnish Army in 2000). Other models available in the chambering include the Blaser LRS2, Erma SR100, Unique Alpine TPG-1, Dakota Longbow, Armalite AR-30, various Barratt models and some Remington 700-based police tactical rifles.

Armed forces, including those of Australia, Canada, Denmark, Finland, Estonia, Germany, Italy, Netherlands, Slovenia, Spain, Switzerland and the UK have adopted the .338. Several countries' police forces (including one or two in Britain according to hearsay) have bought rifles - but I have doubts about their effectiveness, given the cost and logistics of undertaking frequent 1,000yd practice - essential with this type of cartridge and its applications, especially as they are reportedly intended for use in airport hostage situations where a first-shot hit is essential.

With an unusual amount of information about the development of the cartridge in the public domain there will, just this once, be a second part to this look at the .338 Lapua next month covering development, ballistics, target shooting and handloading data.

SPORTS STARS: THE .338 LAPUA MAGNUM PART ONE

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SPORTS STARS: THE .338 LAPUA MAGNUM PART ONE

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