The Precision Sniper Rifle (PSR) was a program by United States Special Operations Command to replace all bolt-action sniper rifles in use by United States special operations snipers with a single bolt-action rifle chambered for a large caliber Magnum round such as .300 Win Mag and .338 Lapua Magnum. The solicitation was placed on January 15, 2009. The contract was awarded to the Remington Modular Sniper Rifle and was designated the Mk 21 Precision Sniper Rifle.[1]