Week Ten Update: Machine Guns During this week your Soldier will spend some time in the classroom getting instruction and familiarization on the M249 Squad Automatic Weapon. commonly referred to as the SAW. The M249 is an individually portable. gas operated, magazine or disintegrating metallic link- belt fed, light machine gun with fixed headspace and quick-change barrel feature. The M249 engages point targets out to 800meters. firing the improved NATO standard 5.56mm cartridge. The SAW forms th