The Colt firearms M4 FPB (Federal Property Battlefield) is a military-specification variant of the M4 carbine. It is chambered for the 5.56x45mm cartridge and is equipped with a 16.1 inches barrel featuring a 1:7 twist rate, optimizing it for the stabilization of heavier projectiles. The rifle includes a detachable carry handle and a picatinny rail, facilitating the attachment of various optical devices. It is designed with a 6-position collapsible stock and a standard A2 pistol grip to enhance ergonomic handling. Additional features include a birdcage flash hider and a low-profile gas block. The M4 FPB supports a 30-rounds magazine and has an approximate weight of 6.9 lb. The Colt firearms M4 FPB is a semi-automatic sporting rifle designed to accommodate the 5.56x45mm cartridge The product is equipped with a 16.1 inches barrel, Magpul backup sights, a Magpul CTR 4-position stock, a Geissele 13 inches MK4 rail, a single-stage trigger and includes one 30-rounds magazine