A Battle Rifle or Main Battle Rifle is a military longarm firing a full sized rifle cartridge. It may be manually operated, self loading (semi automatic) or capable of selective fire. It is designed to effectively engage targets at ranges in excess of 500 meters with individually aimed fire. Someone (possibly Jeff Cooper) once classified these rifles in "phases": a Phase 1 rifle is a military bolt action, such as the Mauser or Lee Enfield rifles; a Phase 2 rifle would be a semi-automatic military rifle, like the Garand or SVT-40; and finally the Phase 3 rifle, a select fire rifle in a full sized rifle cartridge, almost always 7.62x51mm. In practice use of the fully automatic mode of fire was discouraged or disabled in most militaries, due to excessive recoil. The Battle Rifle has been replaced in common use by the shorter ranged assault rifle firing cartridges of reduced power.

Examples of cartridges used in battle rifles are the .303 British, 8x57mm 7.62x54mm and 7.62x51mm.