Major Components of the M240B
(1) Barrel assembly. - Consists of the barrel, flash suppressor, carrying handle, heat shield, front sight assembly, and gas-regulator plug. Houses the cartridge for firing and directs the projectile.
(2) Heat shield assembly. - Protects the gunner's hand from a hot barrel.
(3) Buttstock/buffer assembly and bufferand spade grip assembly/buttstock and buffer assembly. - Composite buttstock: buffer housing that contains spring washers to absorb recoil from bolt and operating rod assembly at the end of recoil movement.
(4) Receiver assembly. Consists of receiver, handguard, bipod, and rear sight assembly. Serves as support for all major components. Houses action of the weapon and, through a series of cam ways, controls function of weapon.
(5) Handguard assembly (not shown). - Provides thermal insulation to protect the gunner's hands from heat or extreme cold.
(6) Cocking handle assembly. - Pulls the moving parts rearward. Moves in a guide rail fixed to the right side of the receiver.
(7) Trigger housing assembly. - Controls the firing of the machine gun. Contains trigger and safety components
(8) Sling and snap hook assembly. - Provides a means of carrying the weapon.
(9) Bipod. - Supports M240B machine gun in prone position.
(10) Drive spring rod assembly. - Provides energy for returning bolt and operating rod assembly to firing position.
(11) Bolt/operating rod assembly. - Provides feeding stripping, chambering, firing, extracting, and ejecting of cartridges using propellant gases for power.
(12) Cover assembly. - Feeds linked belt, positions and holds cartridges in position for stripping, feeding, and chambering. Top rail configuration allows mounting of optical and electronic sights.
(13) Feed tray. - Serves as guide for positioning cartridge to assist in chambering. Has a slotted top to allow air to circulate around barrel for cooling purposes.
(14) Tripod assembly (not shown). - The tripod T&E mount assembly is flexible, provides a stable mount, absorbs recoil, and improves accuracy.
(15) Ejection port. - Provides guide for ejection of spent cartridges.