The U.S. Army has ordered 38.4 million rounds of .300 Winchester magnum ammunition for its newly modified M-24 sniper rifles, as well as similar SOCOMs Mk13 models. The new ammo will cost about $1.30 per round. The .300 Winchester magnum will be ordered in minimum lots of 56,160 rounds (117 boxes of 480 rounds each). The entire 38.4 million rounds will last a while.
All this is in response to requests from snipers for a longer range weapon, but not one as bulky and heavy as the 30 pound .50 caliber rifle (which is good to about 2,000 meters). Thus the army is modifying existing M24 rifles to fire the more powerful .300 Winchester Magnum round. It was felt that this gave the snipers all the additional range they needed, without requiring a much heavier rifle. SOCOM has been using this approach since the early 1990s.
The calls were loudest from snipers operating in Afghanistan, where U.S. Army and Marine Corps shooters wanted a sniper rifle that can consistently get kills out to 1,800 meters. The current 7.62mm round was good only to about 800 meters. The 300 Winchester magnum is a more powerful, but not much larger, round than the current 7.62mm one. By replacing the barrel and receiver of the $6,700 M24 sniper rifle, for about $4,000, you can fire the .300 Winchester Magnum round. This is longer (at 7.62 x 67mm) than the standard 7.62x51mm round, and is good out to 1,200 meters. An improved version of the round is expected to extend that range another 200 meters or so.
There was another option, and that was to replace the barrel and receiver of the M24 sniper rifles to handle the .338 (8.6mm) Lapua Magnum round. Thus you still have a 17 pound sniper rifle, but with a round that can hit effectively out to about 1,600 meters. British snipers in Iraq, and especially Afghanistan, have found the Lapua Magnum round does the job at twice the range of the standard 7.62x51mm round. The 8.6mm round entered use in the early 1990s, and became increasingly popular with police and military snipers. Dutch snipers have used this round in Afghanistan with much success, and have a decade of experience with these larger caliber rifles. British snipers in Afghanistan are also using the new round, having converted many of their 7.62mm sniper rifles. Recognizing the popularity of the 8.6mm round, Barrett, the pioneer in 12.7mm sniper rifles, came out with a 15.5 pound version of its rifle, chambered for the 8.6mm. But the U.S. preferred the lighter .300 Winchester magnum solution.
This is not the first time the U.S. Army has quickly responded to sniper needs. Two years ago, in response to requests from snipers operating in urban areas of Iraq, the U.S. Army began issuing the M110 SASS (Semi-Automatic Sniper System). Urban snipers often have multiple targets, at relatively short ranges. They needed a semiautomatic rifle. Previously, many snipers have had success using tuned up M-14s (from the 1960s) as sniper rifles. While semi-automatic and rugged, the M-14 wasn't designed to be a sniper rifle. The M110 was a better semi-automatic sniper rifle, since it is inherently more reliable and accurate. As far back as World War II, it was known that there were many situations where a semi-automatic sniper rifle would come in handy. But it's taken over half a century to solve the reliability and accuracy problems.
The M110 is a based on the AR-10 rifle. The U.S. Navy has been buying a similar weapon, the SR25. This is also known as the Mk11 Sniper Rifle System (SRS). These new semi-automatic sniper rifles are 7.62mm weapons based on the designs of M-16 creator, Gene Stoner. The basis for the M-16 was the AR-15, and a 7.62mm version of that weapon was called the AR-10. About half the parts in the SR25 are interchangeable with those in the M-16. The Stoner sniper rifles achieved its high accuracy partly by using a 20 inch heavy floating barrel. The "floating" means that the barrel is attached only to the main body of the rifle to reduce resonance (which throws off accuracy.)
The M110 weighs 17.3 pounds in combat, and about 70 pounds with all components of the system. The M110 can use a ten or twenty round magazine. The 40.5 inch long rifle can have a six inch tube attached to the barrel, which reduces the noise and flash made when the rifle fires, and largely eliminates nearby dust rising into the air, which often gives away the snipers position.
The M110 will gradually replace many of the bolt-action M24s, while the remaining M24s will be converted to fire the .300 Winchester Magnum, for those snipers working somewhere, like Afghanistan, where more range is needed..