In the last decade, American soldiers and marines have greatly increased their use of snipers. This can be seen from the fact that the American sniper with the most kills ever, former Navy SEAL Chris Kyle, had 160 confirmed kills (and 95 unconfirmed). Most of these were achieved during four tours in Iraq. The previous record holder, with 109 confirmed kills, was Vietnam era soldier Adelbert Waldron.
Chris Kyle set his record in part because of the more aggressive use of snipers in the last decade. In that time, because of Iraq and Afghanistan, infantry tactics have changed considerably. This has largely gone unnoticed back home, unless you happen to know an old soldier or marine that remembers the old style of shooting. Put simply, the emphasis is on a lot fewer bullets fired and much more accurate shooting. Elite forces, like the Special Forces and SEALs, have always operated this way. But that's because they had the skill, and opportunity to train frequently, to make it work. The army and marines have found that their troops can fight the same way with the help of some new weapons, equipment, and tactics, plus lots of combat experience and specialized training. This includes the use of new shooting simulators, which allows troops to fire a lot of virtual bullets in a realistic setting, without all the hassle and expense of going to a firing range.
One thing that helped, and that was developing for two decades, was the greater use of snipers. Currently, about ten percent of American infantry are trained and equipped as snipers. Commanders have found that filling the battlefield with two man (spotter and shooter) sniper teams not only provides more intelligence, but also a lot of precision firepower. Snipers are better at finding the enemy, and killing them with a minimum of noise and fuss. New rifle sights (both day and night types) have made all infantry capable of accurate, single shot, fire. With the emphasis on keeping civilian casualties down, and the tendency of the enemy to use civilians as human shields, lots of snipers, or infantrymen who can take an accurate shot at typical battle ranges (under 100 meters), are the best way to win without killing a lot of civilians.
New sniper equipment has made a big difference. During the last decade the U.S. Army has issued several new sniper rifles. The M110 SASS (Semi-Automatic Sniper System) was delivered to troops in Iraq and Afghanistan four years ago. This weapon is not a big technological breakthrough. It is based on the older AR-10 rifle. The U.S. Navy had already been buying a similar weapon, the SR25 since the early 1990s. The SR25 was also known as the Mk11 Sniper Rifle System (SRS). These new semi-automatic sniper rifles are 7.62mm weapons based on the M-16 design elements. 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 rifle 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 7.9 kg (17.3 pounds) in combat, and about 32 kg (70 pounds) with all components of the system. The M110 can use a ten or twenty round magazine. The 1.03 meter (40.5 inch) long rifle can have a 15 cm (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 sniper's position. In the last few years, snipers have had the use of more powerful rounds (like the .338 Lapua Magnum and the .300 Magnum) and ever more useful accessories. Several sniper rifle models were modified to handle the longer range rounds.
Previously, many snipers have had success using tuned up M-14s (from the 1960s) as sniper rifles. While semi-automatic and rugged, the M14 wasn't designed to be a sniper rifle. The AR-10 was a better model for a 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 has largely replaced the bolt-action M24, and provided commanders with much more effective snipers. That increase in numbers (of snipers) and their effectiveness, has changed the look (less random fire from U.S. troops) and feel (the U.S. troops appear more in control) of the battlefield. It's also easier to spot the enemy. He's usually the guy firing on automatic. The fellows firing one shot at a time are the Americans, and they are usually the last ones standing.