5.56 NATO & .223 Wylde AR-15 Pistol Uppers (4.5"–13.9")

AR-15 5.56 NATO Pistol Upper Assemblies

5.56 AR pistol uppers are complete AR-15 upper assemblies with barrels shorter than 16". Moriarti Armaments builds them in Miami in 5.56 NATO and .223 Wylde, from 4.5" and 5" Micro ARP uppers to 7.5" and longer pistol-length uppers up to 13.9".

4.5", 5" and 6" ARP uppers

The shortest uppers we make. Most use a 4" or 4.2" M-LOK handguard, which is why shooters often search for a "4 inch ARP upper". Options include suppressor-ready, Cookie Cutter, Spitfire, Gradient, Sidewinder and Shark Flag uppers, plus multi-caliber 4.5" uppers with a mini can.

7.5" AR pistol uppers

The classic AR pistol length, with 7" slim or 9" M-LOK handguards. Choose from Cerakote colors, Diamond Cut, Gold Pineapple, Pentagram, color-accent and fake-can uppers.

10.5" to 13.9" uppers

Longer pistol-length uppers in 10.5", 11.5", 12.5" and 13.9" for more velocity while staying compact. For 16" barrels, see our 5.56 NATO & .223 Wylde uppers.

5.56 pistol upper FAQ

What barrel lengths are considered pistol-length AR-15 uppers?

Moriarti groups its compact 5.56 NATO and .223 Wylde AR-15 uppers from 4.5" through 13.9" in this pistol-length category. Available configurations can include Micro ARP and more traditional AR pistol barrel lengths. The term describes this category's barrel-length range; always check the individual upper for its exact barrel and gas-system specifications.

What is a "4 inch ARP upper"?

It usually means a Micro ARP upper with a 4" handguard. On our uppers the barrel itself is 4.5" or 5", and the muzzle device sits just past the handguard.

Will a 5.56 pistol upper fit my AR-15 lower?

Our 5.56 NATO and .223 Wylde uppers are built for standard mil-spec AR-15 lower receivers. Check each listing for what is included, such as the bolt carrier group and charging handle.

Prefer a complete gun? See our MA-15 5.56 pistols.