Daniel Defense 5.56mm Government Profile 10.3" Barrel - Carbine Gas - 1:7 Twist

Daniel Defense 5.56mm Government Profile 10.3" Barrel - Carbine Gas - 1:7 Twist

Build the ultimate close-quarters battle rifle or authentic Mk18 clone with the Daniel Defense 10.3″ 5.56mm Carbine Gas 1:7 Government Profile Barrel. Renowned across military special operations and law enforcement units as the ballistic core of the legendary CQBR/Mk18 platform, this 10.3-inch barrel delivers the ideal balance between tight-space maneuverability and reliable 5.56 NATO terminal performance. Engineered for demanding duty environments, it provides rapid target transitions and dependable cyclic operation in confined spaces, vehicle operations, and room-clearing scenarios without sacrificing downrange accuracy.

Every Daniel Defense barrel is produced from start to finish in their state-of-the-art facility in Black Creek, Georgia, utilizing proprietary cold hammer forging (CHF). Under intense hydraulic pressure from carbide steel hammers, the barrel steel is forged around a precision-ground mandrel to form the chamber, lands, and grooves simultaneously. This cold-working process aligns the molecular grain structure of the steel, eliminating microscopic interior imperfections and creating the most consistent, concentric chamber and bore possible. Cold hammer forging yields a significantly denser, longer-lasting barrel that resists throat erosion and mechanical wear far better than conventional button-rifled or cut-rifled alternatives.

Constructed from mil-spec Chrome Moly Vanadium (CMV) steel, the barrel features a heavy-duty chrome-lined interior to withstand extreme heat, aggressive cyclic firing schedules, and corrosive particulate wear. The exterior is coated in a rugged, non-reflective Mil-Spec Heavy Phosphate finish for maximum resistance to moisture, abrasion, and environmental elements. Configured with a versatile 1:7-inch twist rate to stabilize heavy 62gr to 77gr combat projectiles (such as Mk262 and M855A1), a standard .750-inch gas block seat, standard carbine-length gas porting, and an A4/M4 feed-ramp barrel extension, this barrel arrives ready for hard-use duty builds and is backed by the Daniel Defense 100% Satisfaction Guarantee.

Features

Cold Hammer Forged (CHF) Precision Mandrel Manufacturing:
Forged under massive hydraulic pressure around a precision mandrel to create an ultra-consistent chamber, bore, and rifling profile with a denser molecular grain structure for maximum barrel life.

Iconic 10.3″ Mk18 / CQBR Architecture:
Engineered to the definitive 10.3-inch length made famous by elite military CQBR platforms, maximizing compact weapon handling while preserving terminal 5.56 velocity.

Mil-Spec Chrome Moly Vanadium (CMV) Steel:
Machined from certified CMV alloy steel, delivering the high tensile strength, fatigue resistance, and thermal tolerance demanded by professional end-users.

Heavy-Duty Hard Chrome-Lined Bore & Chamber:
Features an industrial hard chrome interior lining that prevents chamber corrosion, facilitates smooth extraction, and dramatically slows throat erosion during sustained firing schedules.

Mil-Spec Heavy Manganese Phosphate Exterior Finish:
Treated with an aggressive phosphate outer coating that provides lasting defense against harsh weather, surface abrasion, and duty solvents.

Fast 1:7″ Twist Rate:
Optimized to stabilize a wide spectrum of modern duty and match ammunition, excelling with heavy 69gr to 77gr match and barrier-blind cartridges.

Standard .750″ Gas Block Journal & Carbine Gas System:
Features a reliable carbine-length gas configuration paired with an industry-standard .750-inch gas block seat, providing seamless compatibility with low-profile gas blocks and standard FSBs.

A4 / M4 Barrel Extension with Extended Feed Ramps:
Equipped with a factory-installed M4 barrel extension with extended feed ramps to ensure reliable, hang-up-free cartridge feeding under rapid semi- or full-automatic fire.

Daniel Defense 100% Satisfaction Guarantee:
Manufactured 100% in-house in Black Creek, GA, and supported by Daniel Defense’s comprehensive manufacturer guarantee against defects in materials and craftsmanship.

Specifications