When the Barrett company introduced the .50 caliber (12.7mm) sniper
rifle in the 1980s, it was not the only company working on the concept. The
Steyr-Mannlicher company, of Austria, was also developing on a large caliber
"anti-material" sniper rifle. Barrett quickly took most of the market, but
Steyr continued to work on their weapon. Along the way, they upped the caliber
to 15.2mm, and focused on discarding sabot ammo fired from a smoothbore barrel.
The discarding sabot technique was first used with anti-tank guns. Most modern
120mm tank guns fire a shell that uses a smaller 25mm "penetrator". The 25mm
rod of tungsten (or depleted uranium) is surrounded by a "sabot" that falls
away once the shell clears the barrel. This gives the penetrator higher
velocity, and penetrating power. Each round weighs 5.25 ounces and is eight
inches long. The Stery 15.2mm delivers a .7 ounce (20 gram) tungsten "dart",
that moves at 4700 feet per second, and can go through 40mm (1.5 inches) of
armor at 1,000 meters. The weapon is called the IWS (Infantry Weapon System)
2000, has a 48 inch smoothbore barrel and weighs 40 pounds. It uses a five
round box magazine. The weapon breaks down into two loads, so a two man sniper
team can easily carry it. It's a bullpup design (with the magazine behind the
trigger) that is 5.6 feet in length overall.
is uncertain if there is much of a market for the weapon. The 12.7mm sniper
rifles have about the same sniping performance as the IWS 2000, and Barrett
introduced a 25mm rifle back in 2004. However, the dependence on discarding
sabot ammo only may prove interesting. Discarding sabot rounds have been around
in infantry weapons for some years. They are available for 7.62mm and 12.7mm
weapons, and are interchangeable with standard ammo. The 7.62mm discarding
sabot has a 5.56mm penetrator, and the 12.7mm round uses a 7.62mm penetrator.
However, using a discarding sabot in a rifled weapon does not give you as much
speed as a smoothbore. But that's not much of an edge. Then again, it may be
enough for the Steyr 15.2mm rifle to catch on.