FN America Barrel, 14.7", 5.56 NATO, 1:7 Twist, Hammer Forged – Carbine Gas, M4 Contour – Matte Black
SKU: 20-100405 • MPN: 20100405 • UPC: 845737011147 Shooting Surplus
Upgrade your AR-15 with genuine FN quality. The FN America 14.7" Hammer Forged 5.56 NATO Barrel is built for shooters who want battle-proven durability, excellent accuracy, and a compact carbine-length configuration. Featuring a cold hammer forged, chrome-lined bore, M4 contour, and carbine-length gas system, this barrel is designed to handle high round counts, rough conditions, and demanding training cycles without compromising reliability. Shooting Surplus+2Palmetto State Armory+2
Built by FN – Battle-Proven Barrel Technology
FN is known worldwide for building machine gun and service rifle barrels that withstand extreme use. This AR-15 barrel benefits from that same pedigree:
Cold Hammer Forged (CHF) construction – FN uses a proprietary Chrome Moly Vanadium steel and hammer forging process, the same technology applied to their military machine gun barrels, for exceptional strength and barrel life. Palmetto State Armory+1
Magnetic Particle (MP) tested – Each barrel is individually inspected to ensure it is free from hidden flaws or micro-stresses, delivering consistent performance from barrel to barrel. Palmetto State Armory+1
Chrome-lined bore and chamber – A thick chrome lining increases corrosion resistance and helps maintain accuracy under sustained firing, even when the barrel gets hot. Lafayette Shooters+2RifleGear+2
This combination of materials, forging, and inspection means you’re getting a true duty-grade barrel designed to go the distance.
Optimized 14.7" Carbine Configuration
The FN America 20-100405 barrel is purpose-built for compact, carbine-style AR-15 builds: Shooting Surplus+1
Length: 14.7 inches
Caliber: 5.56x45mm NATO (also compatible with .223 Remington)
Gas System: Carbine-length – a proven, time-tested gas system for reliability and parts compatibility.
Contour: M4 profile – shoulder cuts forward of the gas block to match classic M4-style builds and components.
A 14.7" barrel strikes a great balance between maneuverability and ballistic performance, giving you the handling of a compact carbine while still providing solid velocity for duty, defense, or training use.
1:7 Twist for Modern 5.56 Loads
The 1:7 twist rate is a true mil-spec standard designed to stabilize heavier bullets often used in modern 5.56 NATO loads. Shooting Surplus+1
Benefits of the 1:7 twist include:
Excellent stability with 62–77 grain bullets, including many duty, defensive, and match loads.
Versatility to run a wide range of bullet weights commonly found in 5.56 ammunition.
Consistent performance at practical carbine distances, whether you’re zeroing at 50/200 or stretching out further.
If you’re running heavier OTM, barrier, or match ammo, this twist rate is exactly what you want.
Durable, Protective Finish & M4 Features
FN finishes this barrel to stand up to field use, weather, and hard training:
Matte black manganese phosphate finish – a classic, durable military-style finish that resists corrosion and wear while keeping glare to a minimum. Lafayette Shooters+2Bauer Precision+2
M4 style feed ramps and barrel extension – designed to promote smooth, reliable feeding in AR-15 platforms using standard M4-type upper receivers. Bauer Precision+1
Standard AR-15 compatibility – designed to fit AR-15 pattern rifles using 5.56 NATO components and carbine-length gas systems. Shooting Surplus+1
The result is a barrel that not only performs, but also looks right at home on professional-grade carbines, clones, and hard-use builds.
Key Specifications – FN America 20-100405 / 20100405
From multiple FN-authorized dealers and product listings, this barrel’s core specs include: Valhalla Tactical Supply+3Lafayette Shooters+3Shooting Surplus+3
Manufacturer: FN America
Model / SKU: 20-100405
MPN: 20100405
UPC: 845737011147
Length: 14.7"
Caliber: 5.56x45mm NATO
Twist Rate: 1:7 RH
Gas System: Carbine-length
Contour: M4 profile
Material: Chrome Moly Vanadium steel
Process: Cold hammer forged
Lining: Chrome-lined bore and chamber
Finish: Matte black / black phosphate
Platform: Fits AR-15 pattern rifles
These specifications make it easy to match this barrel to your existing or planned components.
Why Choose the FN America 14.7" Hammer Forged Barrel?
1. True Duty-Grade Durability
Thanks to its CHF construction, thick chrome lining, and high-grade steel, this barrel is made for high round counts, intense training, and long-term use. It’s built using the same processes FN applies to machine gun barrels designed for sustained fire. Palmetto State Armory+2Top Brass Tactical+2
2. Reliable, Proven 5.56 NATO Performance
Chambered for 5.56 NATO, this barrel handles standard-pressure and higher-pressure duty loads reliably while also accepting .223 Remington. Combined with the 1:7 twist, it’s an excellent match for modern defensive and service-style ammunition. Shooting Surplus+1
3. Ideal for Compact Carbine Builds
The 14.7" length with carbine gas is a classic configuration for AR-15 carbines. It offers fast handling, good balance, and easy integration with common rail systems, front sight bases, and carbine-length handguards or free-float setups. RifleGear+1
4. FN Branding and Quality Control
When you choose an FN barrel, you’re choosing a manufacturer with decades of experience building military-grade weapons and components. The rigorous forging, finishing, and testing processes ensure that what you get is not just another AR barrel—it’s an FN barrel. FN® Firearms+2Palmetto State Armory+2
Ideal Uses for This Barrel
The FN America 14.7" 5.56 NATO Hammer Forged Barrel is an outstanding choice for:
Duty-style AR-15 builds inspired by proven military and LE carbines
Hard-use training rifles where high round counts and reliability matter
Home defense or general-purpose carbines that demand durability and consistent accuracy
Enthusiast builds where genuine FN components and mil-spec style are important
Whether you’re assembling a rugged work rifle, cloning a service carbine, or simply upgrading your current AR with a premium, long-life barrel, this FN barrel is a top-tier foundation.
SEO-Focused Summary
The FN America Barrel, 14.7", 556NATO, 1:7 Twist, Hammer Forged, Carbine Gas System, M4 Contour, Fits AR-15, Matte Finish, Black (20-100405 / 20100405 / UPC 845737011147) is a cold hammer forged, chrome-lined, M4-profile AR-15 barrel built from Chrome Moly Vanadium steel and finished in durable matte black phosphate. With its carbine-length gas system, 1:7 twist rate, and FN’s battle-proven barrel manufacturing process, this 14.7" 5.56 NATO barrel delivers exceptional durability, reliability, and accuracy for serious AR-15 builders and shooters looking for a true duty-grade component. Valhalla Tactical Supply+3Lafayette Shooters+3Shooting Surplus+3
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