The FN M249S is a semi-automatic version of the M249 SAW light machine gun, originally developed by FN Herstal and adopted by the U.S. military in 1988. This civilian variant mirrors the military M249 SAW’s design but operates in semi-automatic mode. It features an 18.5-inch barrel made from cold hammer-forged steel and lined with hard chrome, enhancing durability and accuracy. The rifle’s closed-bolt operation ensures reliable performance, and it is chambered for 5.56x45mm NATO cartridges. It supports both magazine and linked belt ammunition, for various shooting needs. The FN M249S includes several notable features that reflect its military lineage. Its robust gas system and quick-change barrel capability facilitate sustained fire and adaptability in different conditions. The receiver is constructed from formed steel and includes a claw extractor for dependable case ejection, alongside a fixed, pivoting ejector and side ejection port. The top cover integrates a MIL-STD-1913 rail for mounting optics, while a folding steel bipod and carry handle enhance maneuverability and ease of transport. The highly ergonomic polymer buttstock is equipped with a hydraulic recoil buffer and a non-slip buttplate, improving control and comfort. The redesigned trigger mechanism and non-reciprocating charging handle contribute to a smoother shooting experience. The FN M249S employs a standard disintegrating link belt-feed system and includes an under-mounted polymer ammunition container to keep ammunition cleaner and reduce wear.