High Quality Content by WIKIPEDIA articles! A recoilless rifle (RCLR) or recoilless gun is a lightweight weapon that fires a heavier projectile than would be practical to fire from a recoiling weapon of comparable size. Technically, only devices that use a rifled barrel are recoilless rifles. Smoothbore variants are recoilless guns. This distinction is often lost, and both are often called recoilless rifles.