Enjoy free shipping during the holidays! Shop now and get
Free Value Shipping
on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.
Enjoy Our Extended FREE RETURNS
We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended
Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended
return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later).
We'll even cover the cost of return shipping. Learn more about our
Return Policy.
Please Enable Your Browser's Cookies Functionality
Cookies are not currently enabled in your browser, and due to this the functionality of our site will be severely restricted.
Web browser based cookies allow us to customize our site for you, save items in your cart,
and provide you with a great experience when shopping OpticsPlanet.
Your privacy is important to us, and any personal information you supply to us is kept strictly confidential.
If you cannot enable cookies in your browser, please contact us — we are always here to help!
JavaScript is blocked by AdBlocker or ScriptBlocker
We're sorry - it looks like some elements of OpticsPlanet are being disabled by your AdBlocker.
Unfortunately we are unable to offer our excellent shopping experience without JavaScript.
Please add "opticsplanet.com" and "https://opl.0ps.us/assets-9ba29201094/" to whitelist,
or disable AdBlocker for this site (please note that we do NOT feature any annoying ads on this website).
Thanks!
Your Browser is Outdated
Unfortunately, we are unable to provide an excellent shopping experience on your browser because it lacks modern functionality needed for us
to provide a fast, secure, and enjoyable experience. If you cannot upgrade your browser or use an alternative device to visit us,
please contact us at +1-800-504-5897 and we'll be happy to assist you over the phone!
FN America AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO 36421 Up to 13% Off and Clearance w/ Free Shipping — 2 models
This is my barrel of choice. I have used this barrel on other guns, and I always get great results. The barrel is chrome lined and is produced in a factory that was building weapon barrels before WWII. It's the best that is out there....
Product Info for FN America AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO 36421
Chrome lined chamber and bore. Hammer forged from proprietary Chrome Moly Venadium (CMV) steel. This is the same steel developed for our Machine Gun barrels designed to handle the punishment of full-auto fire now available to you in our AR-15 barrels. Magnetic Particle (MP) tested to ensure each barrel is free of microstresses and/or cracks. Government Profile, built for .750 inch diameter gas block, ½ x 28 inch threaded muzzle. M4-style feed ramp and barrel extension for consistent and reliable feeding. Manganese Phosphate barrel finish. 1:7 inch right hand twist rate.
Specifications for FNH USA AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO 36421:
Mfg Item Num:
 36421
Type:
 BARRELS - RIFLE
Barrel Length:
 16
Caliber:
 5.56mm NATO
Caliber-Gauge:
 .223 REM.
Model Header:
 Carbine Length Gas System
Master Model Header:
 AR-15 Hammer Forged Barrels
FN America AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO 36421 Orderable Models
List of Orderable Models
FN America AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO, MPN: 36421, UPC: 845737005122, Code: 57D-ATB-36421
USED FN America AR-15 Hammer Forged 16 Inch Barrel Carbine Length Gas System 5.56mm NATO, EDEMO1, Condition Parts Only/Salvage, Defective, MPN: 36421-EDEMO1, Code: 57D-ATB-36421-EDEMO-DF-F