Designated Marksman Rifle

A designated marksman rifle (DMR) is the weapon used by soldiers in the designated marksman (DM) role. The DM's role fills the gap between a regular infantryman and a sniper, typically being deployed at ranges of 250-600 m (273.4-656.17 yards). DMRs have been developed with this middle ground in mind.

These rifles have to be effective, in terms of accuracy and terminal ballistics, at ranges exceeding those of ordinary assault rifles (250 m or less), and battle rifles, (up to 500 m) but do not require the extended range of a dedicated sniper rifle (typically employed for targets at ranges from 500 m - 2 km).

DMRs, however, often share some basic characteristics with sniper rifles when compared to the weapons carried by others in the DMs unit. DMRs may have an attached telescopic sight, quickly deployed stabilizing bipod to allow optimized accuracy and low-recoil in temporarily fixed situations or an adjustable .

They will, though, generally retain semi-automatic firing capability (more rapid than bolt-action sniper rifles) and a larger magazine capacity of 10, 20, or 30 rounds depending on the firearm in question.

Most designated marksman rifles are based on an assault rifle that is currently issued by a nation's military, or on a battle rifle that was formerly issued. A battle rifle is a semi-automatic or full-automatic rifle that fires 7.62mm NATO or similar full-power rounds. Classic examples include the M14, FN FAL, AR-10 and Heckler & Koch G3. These rifles were largely replaced by assault rifles firing the 5.56mm NATO cartridge during the 1980s and 1990s.

...
Wikipedia