It was introduced in 2009, and was designed to meet specific United States Army and USSOCOM Precision Sniper Rifle requirements.
[2] The MSR initially won the PSR competition, and was called the Remington Mk 21 Precision Sniper Rifle in U.S. military service.
The quick-change barrels are free-floated inside the tubular handguard which is provided with a number of user-installable Picatinny type accessory rails.
Additional equipment includes a detachable folding bipod and a quick-detachable suppressor which installs over the specially designed muzzle brake.
The main objective is for the rifle to defeat level IV body armor at 400 meters, whether suppressed or unsuppressed, in temperature ranges of −65 to 160 °F (−54 to 71 °C).