5.56x45mm NATO Receivers

Ar-15 Super Duty Nano Complete Upper Receivers 5.56mm - Ar-15 16 Super Duty Nano Complete Upper Receiver Black

Ar-15 Super Duty Nano Complete Upper Receivers 5.56mm - Ar-15 14.5 Super Duty Nano Complete Upper Receiver Ddc

Ar-15 Super Duty Nano Complete Upper Receivers 5.56mm - Ar-15 14.5 Super Duty Nano Complete Upper Receiver Black

Mk16 Super Duty Complete Upper Receivers 5.56mm - Mk16 11.5'''' Super Duty Upper Chf Bbl, Ach, Nano Fh/Bcg Ddc

M4e1 5.56mm Assembled Upper Receiver W/Gen-2 Handguard & Fsb - M4e1 5.56 Assm Uppr Rcvr Gov 10.5'''' Bbl Carbine W/7''''hg & Fsb

LMT Defense DEFENDER-L Stripped Lower 5.56 / .300 AAC Blackout

BLEM Bravo Company Complete Lower w/ BCM Gunfighter Stock

Bravo Company Lower Group w/ Milspec M4 Stock Black 5.56 / .223 Rem

Ar-15 16'''' Lo-Drag Bull Upper Receivers - Ar-15 16'''' Lo-Drag Bull Upper Receiver Ff Hg 1-7

Ar-15 16'''' Lo-Drag Bull Upper Receivers - Ar-15 16'''' Lo-Drag Bull Upper Receiver 2pc Hg 1-7

Stag 15 5.56 18in 3gun Elite Upper Receivers - Ar-15 3 Gun Elite Upper Receiver 5.56mm Left Hand

RUGER AR-556 Elite 5.56 NATO Complete AR15 Lower Receiver - Black w/ Magpul MOE SL Stock

ANDERSON AR-15 Stripped Lower Multi Cal

PRI Mark 12 Mod 0 Gen II AR-15 Complete Upper Receiver 5.56x45mm NATO 18" Barrel 1:8" Twist Flat Dark Earth

PRI Mark 12 Mod 0 Gen II AR-15 Complete Upper Receiver 5.56x45mm NATO 18" Barrel 1:7" Twist Black

Mike 15 Gen 2 5.56 Upper Receivers - Gen 2 Complete Upper 9'''' Pistol Length Gas W/Blast Diverter

Mike 15 Gen 2 5.56 Upper Receivers - Gen 2 Complete Upper 13.9'''' Intermediate Gas W/A2 Flash Hider

Mike 15 Gen 2 5.56 Upper Receivers - Gen 2 Complete Upper 16'''' Intermediate Gas W/A2 Flash Hider

Black Diamond Specter Xl Top End - Black Diamond Specter Xl Top End 5.56mm Nato 16'''' Bbl 1-8

M4e1 Pro Complete Lower Receiver W/ Moe Grip & Sl Carbine Stock - M4e1 Pro Comp Lower W/Moe Grip & Sl Carbine Stock Kodiak

M4e1 Pro Complete Lower Receiver W/ Moe Grip & Sl Carbine Stock - M4e1 Pro Comp Lower W/Moe Grip & Sl Carbine Stock Black

M4e1 5.56 Assembled Upper Receiver W/M-Lok Atlas S-One Handguard - M4e1 5.56 Assm Uppr 16'''' Mid-Len 12'''' M-Lok Atlas S-One Hg Blk

AERO PRECISION M4E1 Cmplt Lower Rcv MOE Grip & PRS Rifle Stock

Ar-15 Super Duty Stripped Upper Receivers 5.56mm - Ar-15 16'''' Top Tier Stripped Super Duty Upper Od Green