5.56 NATO & .223 Wylde AR-15 Upper Assemblies
5.56 NATO & .223 Wylde AR-15 Uppers by Barrel Length
Shop 5.56 NATO and .223 Wylde AR-15 uppers from Moriarti in a wide range of barrel lengths, handguards and finishes. Browse everything from micro ARP and AR pistol uppers to 16-inch carbine and long-barrel rifle configurations. Choose from 5.56 NATO and .223 Wylde chamberings for recreational, target and general-purpose AR-15 applications. Compare each upper for exact barrel length, twist rate, gas system, rail and included components.
What is the difference between a 5.56 NATO upper and a .223 Wylde upper?
A 5.56 NATO upper uses a 5.56 NATO chamber, while a .223 Wylde upper uses a hybrid chamber designed to safely accommodate both 5.56 NATO and .223 Remington ammunition while incorporating chamber geometry intended to support accuracy with .223 ammunition. Always follow the ammunition and specifications listed for the individual barrel.
Refine Search
-37%
4.5" Micro ARP Upper Assembly – 5.56, .300 BLK, 7.62×39 & .338 ARC | Mini Can
The Moriarti 4.5" Micro ARP Upper Assembly with Mini Can is a compact AR-15 upper configuration avai..
-43%
5" 5.56 NATO AR-15 Pistol Upper Assembly – 1:5 5R Barrel, Custom Color Accents
The Moriarti 5" 5.56 NATO AR-15 Pistol Upper Assembly features a 4150 steel barrel with black nitrid..
-38%
5" 5.56 NATO Micro ARP Cookie Cutter Upper Assembly – 4" M-LOK
The Moriarti AR-15 5.56 NATO 5" Cookie Cutter Upper Assembly combines aggressive styling with an ult..
-38%
5" 5.56 NATO Micro ARP Gold Spitfire Upper Assembly – 4" M-LOK
Stand out with the Moriarti Micro ARP AR-15 5.56 NATO 5" Complete Upper Assembly, featuring an eye-c..
-33%
5" 5.56 NATO Micro ARP Gradient Series Upper Assembly – Side-Cut Billet, 4" M-LOK
The Moriarti 5" 5.56 NATO Micro ARP Gradient Series Upper Assembly brings custom styling and distinc..
-45%
5" 5.56 NATO Micro ARP Red Accent Pistol Upper Assembly with Charging Handle
The Moriarti 5" 5.56 NATO Micro ARP Red Accent Pistol Upper Assembly features a compact configuratio..
-33%
5" 5.56 NATO Micro ARP Shark Flag Upper Assembly – Slick Billet, 4.2" M-LOK
The Moriarti 5" 5.56 NATO Micro ARP Shark Flag Upper Assembly combines distinctive custom accents wi..
-47%
5" 5.56 NATO Micro ARP Sidewinder Pistol Upper Assembly – M-LOK
The Moriarti 5" 5.56 NATO Micro ARP Sidewinder Pistol Upper Assembly is part of the Moriarti Micro A..
-30%
5" 5.56 NATO Micro ARP Spitfire Hybrid Upper Assembly – 4" M-LOK
The Moriarti 5" 5.56 NATO Micro ARP Spitfire Hybrid Upper Assembly is part of Moriarti's compact Mic..
-46%
5" 5.56 NATO Micro ARP Suppressor Ready Upper Assembly – 4" M-LOK, A2 Flash Hider
The Moriarti 5" 5.56 NATO Micro ARP Suppressor Ready Upper Assembly is part of Moriarti's Micro ARP ..
-45%
5" AR-15 Suppressor Ready Pistol Upper Assembly – Choose Caliber & Color
The Moriarti 5" AR-15 Suppressor Ready Pistol Upper Assembly is available in 5.56 NATO, .300 AAC Bla..
-47%
AR-15 4.5" Micro ARP Suppressor Ready Pistol Upper Assembly – Multiple Calibers & Colors
The Moriarti 4.5" Micro ARP Suppressor Ready Pistol Upper Assembly is a compact AR-platform upper of..
-36%
AR-15 5.56 NATO 16" Carbine Upper Assembly with 15" M-LOK Handguard | CERAKOTE GRAD Colors | Tactical Charging Handle
Build your dream AR-15 with the Moriarti Arms® 5.56 NATO 16" Carbine Upper Assembly, designed for pe..
-45%
AR-15 5.56 NATO 5" Micro ARP Pistol Upper – Blue Accent
The Moriarti AR-15 5.56 NATO 5" Pistol Upper combines compact Micro ARP styling with distinctive blu..
-38%
AR-15 5.56/.223 16" Govt Profile BLACK SHARK Upper Assembly / MLOK
Upgrade your AR-15 build with the AR-15 5.56/.223 16" "BLACK SHARK" Upper Assembly. Designed for pre..
-38%
AR-15 5.56/.223 16" M4 Carbine Upper with 15" M-LOK Handguard and Claw Muzzle Brake – 1:7 Twist, Carbine-Length, Moriarti Arms
The AR-15 16" M4 Carbine Upper Assembly from Moriarti Arms delivers dependable performance, modular ..
-43%
AR-15 5.56/.223 16" M4 MAGPUL MOE FLAT TOP UPPER ASSEMBLY - OD GREEN
Action: Semi-auto Gas System: Carbine Length Gas System Chamber: 5.56 NATO Muzzl..
-43%
AR-15 5.56/.223 16" M4 Magpul MOE Flat Top Upper Assembly – FDE
Upgrade your AR-15 build with the 5.56/.223 16" M4 Magpul MOE Flat Top Upper Assembly in FDE. Design..
-40%
AR-15 5.56/.223 16" M4 Upper Assembly with Triport Muzzle Brake and M-LOK Handguard - Choose Color
Manufactured by Moriarti Armaments – CA & NY Compliant. Choose color on top of page - available ..
-50%
AR-15 5.56/.223 16" M4 Upper with Magpul MOE Handguard – 1:7 Twist, Carbine-Length, Flat Top – Black | Moriarti Arms
The AR-15 16" M4 Flat Top Upper Assembly with Magpul MOE Handguard delivers rugged reliability and p..
-49%
AR-15 5.56/.223 16" M4 Upper with Red MLOK Handguard & Custom Pineapple Muzzle Brake | Moriarti Arms
Make a statement at the range with the AR-15 5.56/.223 16" M4 Red Upper Assembly with Custom Pineapp..
-50%
AR-15 5.56/.223 16" Stainless Steel Premium Quad Rail Upper – .223 Wylde, 1:8 Twist | Moriarti Armaments
Upgrade your AR-15 with Moriarti's 16” Stainless Steel Premium Quad Upper, designed for performance,..
-28%
AR-15 5.56/.223 16" Stainless Steel Spiral Fluted "Black Shark" Upper Assembly / Mlok
The AR-15 5.56/.223 16 Stainless Steel Spiral Fluted Black Shark Upper Assembly / Mlok is a reliable..
-40%
AR-15 5.56/.223 24" Spiral Stainless Steel Fluted Upper Assembly | M-LOK | Triport Muzzle Brake
Enhance your AR-15 build with the 24" Spiral Stainless Steel Fluted Upper Assembly, engineered for p..