The U.S. Marine Corps has adopted a new sniper rifle; the Mk13. This is a customized version of the older U.S. Army M24 that, among other things, fires the WinMag (.300 Winchester magnum) 7.62x67 round. WinMag is more powerful than the NATO 7.62x51 round currently used in the M24 and the similar marine M40. The Mk13 needs a new receiver and barrel to handle the WinMag and also comes with a new scope, a new flash suppressor and a folding buttstock. The current version of the WinMag round is accurate out to about 1,100 meters, versus 800-900 meters for the NATO 7.62x51.
Back in 2010, the U.S. Army began upgrading 3,600 of their older M24 rifles to the M24E1 which is basically the Mk13. That conversion cost $7,800 per rifle and included receiver and barrel (with flash suppressor) and a new scope. Marines began receiving their Mk13s within months of the decision to adopt that rifle because there were lots of converted M24s available or older ones that could be quickly upgraded. The Marines adopted a more advanced scope than the Army did. The Mk13 Mod 7 has the Nightforce ATACR 5-25×56 F1 scope. The ATACR uses the newly developed Tremor3 reticle, which allows the shooter to quickly adjust aim so that multiple targets can be hit at long distances. The Marines are paying about $10,000 for each Mk13. The WinMag ammo is also more expensive than the older 7.62x51 and snipers require a lot of ammo for training. The Marines have been using the M40 rifle since the 1960s and the M13 is a major improvement.
Meanwhile the Army and special operations troops have gone through several generations of new sniper rifles. For example in 2013 U.S. SOCOM (Special Operations Command) finally (after a four year search) selected their new sniper rifle; the M21 PSR (Precision Sniper Rifle) after competitions made it clear that this modified version of the existing MSR (Modular Sniper Rifle) was the best choice. In early 2013 SOCOM ordered 5,150 PSRs for about $15,000 each, as well as 4.6 million rounds of ammo. The rifles and ammo will be delivered as needed between 2013 and 2022.
The new PSR has been well received and will gradually replace the Mk13 and M40 sniper rifles. The PSR is a bolt action rifle weighing 7.7 kg (17 pounds) and is 1.2 meters (46 inches) long with the stock extended. It is 91cm (36 inches) long with the stock folded. Depending on the barrel installed, it can fire one of five cartridges; .338 (8.6mm) Lapua Magnum, .338 Norma Magnum, .300 Winchester Magnum, .308 Winchester, or 7.62x51 NATO standard. The PSR will mainly use the Lapua Magnum. Max range with the more powerful magnum rounds is 1,600 meters. The PSR uses five or ten round magazines.
The older 6.8 kg (15 pounds) M24 is based on the Remington 700 hunting rifle, as is the 7.5 kg M40. The MSR/PSR is an entirely new design and is also from Remington. The MSR entered service in 2009, and many SOCOM operators saw it as the likely winner of the PSR competition. Many Marines wanted the PSR or at least something with similar range as the PSR. In line with this, the Marines are building a new rifle range for snipers that can handle firing out to 1,846 meters (2,000 yards). The eagerness of the Marines to get a new sniper rifle comes from the experience many of their snipers had with the Taliban in Afghanistan, who figured out they could deal with marine snipers by having their machine-guns fire indirectly (up and over, like artillery). This is less accurate but if you use “area fire” (by putting a lot of bullets in a large area) it works to make life unbearable for snipers. This is an old tactic and if you have enough ammo it works. The Marines were using the M40 which has a max range of about 900 meters. The PSR enables snipers to fire from nearly twice as far away and make it more difficult for enemy machine-gunners to reach them with effective area fire.
The Lapua Magnum round was selected as the standard for the PSR because it has had an impressive track record in combat. The Lapua Magnum first appeared in 1989 and was designed for big game hunters and police snipers. It was a round that can hit effectively out to about 1,600 meters and military snipers soon began to call for its use in their weapons. British snipers in Iraq, and especially Afghanistan, got it early on and found the Lapua Magnum round did the job at twice the range of the standard 7.62x51mm round (developed in the 1950s and based on a round developed before World War I). The 8.6mm round entered military use in the early 1990s and became increasingly popular with police and military snipers. British snipers in Afghanistan had many of their 7.62mm sniper rifles converted (by replacing the barrel and receiver) to use the new round. By 2009, the Americans were also on board and a growing number of their sniper rifles got new barrel/receiver assemblies so the Lapua Magnum could be used.
Since 2003 American soldiers and Marines have greatly increased their use of snipers, and the success of this move spread to other countries. The more aggressive use of snipers in the last decade is one of many changes in ground combat. 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 fewer bullets fired and 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 a lot 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.
Currently, about ten percent of American infantry are trained and equipped as snipers (or “sharpshooters”). 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, a lot 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. Since 2008 U.S. Army has issued several new sniper rifles. The M110 SASS (Semi-Automatic Sniper System) was delivered to troops in Iraq and Afghanistan in 2008. This weapon was not a big technological breakthrough. It is based on the older AR-10 rifle. 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 adopted some more powerful rounds (like the Lapua Magnum and the .300 Magnum) and ever more useful accessories. Several sniper rifle models were modified to handle the longer range rounds (by replacing the barrel and receiver).
Previously, many snipers have had success using tuned up M14s (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.
But for most snipers, the primary job is the long-range shot and for that, a bolt-action rifle is preferred. The commercial Remington 700 hunting rifle had been around since 1948 and went through several design upgrades before stabilizing in 1962. This rifle caught on quickly with many hunters and combat veterans, in particular, were impressed. This by 1966 a militarized version of the Remington 700 appeared as the M40 and two years later as the M24. The Mk13 also went through several upgrades after first appearing in the late 1990s as “Mod 0”. By 2012 is was up to Mod 5 and more upgrades followed to produce the Mk13 Mod 7 the Marines adopted.