Saboted Light Armor Penetrator (SLAP) Ammunition. Designers of anti-armor ammunition have long used the idea of replacing a given caliber gun's projectile with a projectile of smaller diameter but more dense material. In order to seat the smaller projectile in the larger ammunition case, and to gain the necessary spin from the gun's rifled barrel, the projectile is wrapped in a "sabot" or "shoe." The shoe rides the length of the gun's barrel, then drops away from the projectile when it exits the barrel. The much higher velocity of a "saboted" round enhances its armor-piercing performance.
The U.S. Marine Corps developed 50 caliber SLAP ammunition in the 1980s, and it was used in 1990 during the Gulf War's Operation Desert Storm. It uses a .30 inch heavy metal (tungsten) penetrator in a plastic shoe, which is .50 inch in diameter. "Since the mass of the saboted penetrator is much lighter in weight than normal ball .50 caliber ammunition, SLAP's velocity can be significantly and safely increased," according to the Marine Corps. "This produces a very fast round with a very flat trajectory which enhances hit probability...and extends the light armor capability...significantly."58
According to Winchester, the civilian contractor that developed the 50 caliber SLAP round, it delivers "superior and proven performance against lightly armored vehicles and armoured attack helicopters at ranges up to 1500 meters."
Components of "saboted light armor piercing" (SLAP) round
The 30 caliber bullet fits into 50 caliber case with plastic "sabot." Sabot falls away after round exits the barrel of the gun.
Raufoss Multipurpose (Armor-piercing, explosive, incendiary) Ammunition. The crown jewel of 50 caliber sniper rifle ammunition is the Raufoss multi-purpose round, developed by a Norwegian company and manufactured under license by several companies, including Winchester. Said by experts to be the most popular round with U.S. military snipers,60 it was used to devastating effect by U.S. forces in the 1991 Gulf War.
Designated the MK211 by the U.S. military, the Raufoss round was described by Jane's International Defense Review in 1994 as "the most influential development of the past decade" in 50 caliber ammunition.61 The round combines armor-piercing, explosive, and incendiary effects and uses a "highly effective pyrotechnically initiated fuze...[that] delays detonation of the main projectile charge until after initial target penetration—moving projectile fragmentation and damage effect inside the target for maximum anti-personnel and fire start effect."62 According to its developer, Nordic Ammunition Company (NAMMO), the round can be used in "sniper rifles similar to Barrett M82A1," has "the equivalent firing power of a 20 mm projectile to include such targets as helicopters, aircrafts (sic), light armour vehicles, ships and light fortifications," and can ignite JP4 and JP8 military jet fuel.63 (The typical 20mm projectile to which NAMMO equates its 50 caliber Raufoss round is approximately .8 inch in diameter, thus more than half again as wide as the 50 caliber. It is used in anti-armor and anti-aircraft cannons, often with an explosive charge.64 The Vulcan 20mm cannon has been the standard internal gun armament of most U.S. combat aircraft—currently including F-14, F-16, and F/A-18—since the 1950s.65)
According to the Marine Corps, the Barrett "M82A1A...fires the .50-caliber RAUFOSS ammunition, which contains a tungsten penetrator and a more powerful explosive charge than the API ammunition....it has penetrated an inch of steel at 2000 yards."66 Jane's International Defense Review estimates that the round is "probably capable of disabling a man wearing body armor who is standing behind the wall of a house at 2,000m.... (and) can perforate the foundation of a high-rise building (20cm reinforced concrete) at 400m."67 Reasonable persons probably would agree that blasting through 20 centimeters (7.87 inches) of reinforced concrete from four football field's distance is an impressive performance.
The antipersonnel sniping potential of the Raufoss round—touted by both NAMMO and Winchester in their advertising material—inspired an unsuccessful attempt in 1998 by the International Committee of the Red Cross to have the round Raufoss Round declared an "exploding bullet" banned under international law.68