April 26, 2007: The U.S. Army has begun issuing the M110 SASS (Semi-Automatic Sniper System) to troops in Iraq and Afghanistan. This weapon 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, retired USAF Colonel 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.

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 will gradually replace the bolt-action M24 over the next few years.