Navy SEALS Choose Knight's SR25 Sniper Rifle.

• Author: Ezell, Virginia Hart
• Position: Brief Article

After five years of shopping for a new weapon, the U.S. Navy SEALs took the plunge and adopted the 7.62 x 51 mm SR25 sniper rifle, made by Knight's Armament Company, of Vero Beach, Fla., and stirred the precision rifle market in the process.

The Navy let a sole source contract for 300 weapons, in May 2000, after type classifying the weapon and assigning it an official national stock number. Now referred to as the Mk 11 Mod 0, the stock number signifies nor just the SR25 rifle but indicates a full weapon system, including the rifle, a Leopold scope, back-up pop-up iron sights and a lightweight military match suppressor.

The SR25 is a familiar weapon within the civilian precision rifle market. It began as a combination of design ideas from the AR-10 and AR-15 rifles, and uses "over 60 percent of existing M-16 parts" in its construction, according to company literature. More than 3,000 units have been sold to civilian shooters since the rifle was first produced in the early 1990s.

Most of Knight's customers prefer the 24-inch barrel version that outsells other versions at a rate of 9 to 1. It is the only version that the company would guarantee for an out-of-the-box accuracy of less than one minute of angle at 100 yards. The longer barrel version has been popular among civilian marksmen, but at 44 inches, it was too long for military operations. With the suppressor attached, the weapon was 50 inches long.

Designers at Knight's Armament changed the 24-inch barrel of the commercial version to its 20-inch barrel version to meet the SEALs' requirements for a weapon better suited for urban combat. Although this would appear a simple conversion, an exchange of one barrel for another, Knight's engineers knew the 20-inch version was not as accurate as the 24-inch barrel one. They needed to make changes behind the barrel to deliver the same accuracy of the longer version.

When the SR25 was first under development, Eugene Stoner, who originated the idea for the rifle, said he wanted combat soldiers to have the quality of a match rifle without needing a convoy of gunsmiths with them to maintain accuracy. Engineers at Knight's knew there were changes in store if they wanted to maintain that level of quality when they changed the barrel length. The shorter barrel version was inherently less accurate than the longer barrel.

Improving the barrel would not improve the performance of the weapon, because precision is a function of the barrel in combination with...