The M24 SWS (Sniper Weapon System) is the designation given by the US Army to the Remington 700 bolt-action rifle in 1988 when it was adopted as the standard sniper rifle.
The US Marine Corps uses another variant of the Remington 700, designated the M40. The main difference from the rifle used by the Marines is that the Army M24 rifle has a modified bolt that allows it to fire more powerful rounds than those fired by the M40.