Aero Precision M4E1 Complete Upper Receiver, AR-15, 5.56x45mm NATO, 14.5 in Mid Length Barrel, 12 in M-LOK Handguard, No BCG/CH, Magpul Cerakote, Flat Dark Earth, APAR640232M5

Aero Precision AR-15 Complete Upper Receiver, 5.56, Carbine Length, 16 Inch Barrel W/Pinned FSB, Magpul MOE Handguard, A2 Flash Hider, Anodized Black, APAR502503M64

Aero Precision M4E1 Complete Upper Receiver, AR-15, 5.56x45mm NATO, 14.5 in Mid Length Barrel, 12 in Quad Rail Handguard, No BCG/CH, Anodized, Black, APAR640231Q5

Aero Precision AR-15 Complete Upper Receiver, 5.56, Carbine Length, 10.5 Inch Barrel W/Pinned FSB, Magpul MOE SL Handguard, A2 Flash Hider, FDE Cerakote, APAR502506M3

OP Exclusive Moriarti AR-15 Upper Receiver Assembly, 5.56x45mm NATO, 10.5In, Carbine, Government, M-LOK, 1-7 Twist, 1/2X28, Diamond Cut Free-Float Handgrd, Triport Muzzle Brake, Black, MAR-10-556-TRI

Ncstar VISM AR-10 Upper Receiver Block

Aero Precision AR-15 Complete Upper Receiver, 5.56, Rifle Length, 20 Inch Barrel W/Pinned FSB, Magpul MOE Handguard, A2 Flash Hider, Anodized Black, APAR502501M66

CMMG Mk4/AR15 Upper Receiver Assembly, Titanium, 55BA290-TI

Aero Precision AR-15 Complete Upper Receiver, 5.56, Mid-Length, 16 Inch Barrel W/Pinned FSB, Magpul MOE SL Handguard, A2 Flash Hider, FDE Cerakote, APAR502506M65

OP Exclusive Moriarti AR-15 Upper Receiver Assembly, 5.56X45mm, 10.5In, Carbine, Government, M-LOK, 1-7, 1/2X28, Diamond Cut Free-Float Handgrd, A2 Flash Hider, Cerakote, Burnt Bronze, MAR-10-556-BB

Aero Precision AR15 Complete Upper, 16in 5.56 M4 Carbine Barrel W/ Pinned FSB, M4 Handguard ,Includes BCG & CH, Anodized Black, APAR505721

Guntec USA AR Complete .308 Upper Receiver W/O Lower Parts Kit, N.1, 15in M-Lok Handguard, .308 Gen 2 M.L.S. Stock Assembly, Mid-Length, .750 Gas Block, 16in M4 4150 Barrel, 1-10 Twist, 5/8X24 A2 Bird

Stag Arms AR-15 Tactical Upper Receiver, 5.56x45mm NATO, 7.5in Barrel, GOV-CMV Profile, 1-7 Twist, 1/2X28, Left Hand, VG6 Delta, Chromephos, FDE, STAG15111921

Aero Precision M4E1 Complete Upper Receiver, AR-15, 18 in Rifle Length Barrel, 15 in M-LOK Handguard, No BCH/CH, Magpul Cerakote, Flat Dark Earth, APAR640252M8

Aero Precision AR-15 Complete Upper Receiver, 5.56, Carbine Length, 10.5 Inch Barrel W/Pinned FSB, Magpul MOE SL Handguard, A2 Flash Hider, Anodized Black, APAR502505M3

Guntec USA AR Complete .308 Upper Receiver W/O Lower Parts Kit, N.5, 15in M-Lok Handguard, .308 Gen 2 M.L.S. Stock Assembly, Mid-Length, .750 Gas Block, 16in M4 4150 Barrel, 1-10 Twist, 5/8X24 A2 Bird

Guntec USA AR-15 Complete 5.56 Upper Receiver W/O Lower Parts Kit, N.4, 15in Air-Lok M-Lok Handguard, MLS Gen 2 Stock Assembly, Carbine Length, .750 Gas Block, 16in 5.56mm M4 4150 Barrel, 1-7 Twist, 1

Luth-AR Complete Upper Receiver Assembly, .223, 26In, 16In, Bull, Carbine, 1X9, 1/2X28, Picatinny, Key MOD, A2 Flash Hider, Anodized, Manganese Phosphate, Silver/ Black, FTBL-B16

Stag Arms AR-15 Tactical Upper Receiver, .300 AAC Blackout, 8in Barrel, GOV-CMV Profile, 1-7 Twist, 1/2X28, Left Hand, VG6 Delta, Black, STAG15112122

Guntec USA AR-15 Complete 5.56 Upper Receiver W/O Lower Parts Kit, N.1, 15in Ultralight M-Lok Handguard, MLS Gen 2 Stock Assembly, Carbine Length, .750 Gas Block, 16in 5.56mm M4 4150 Barrel, 1-7 Twist

Guntec USA AR-15 Complete 5.56 Upper Receiver W/O Lower Parts Kit, N.5, 15in Ultralight Series M-Lok Handguard, MLS Gen 2 Stock Assembly, Carbine Length, .750 Gas Block, 16in 5.56mm M4 4150 Barrel, 1-

Aero Precision M4E1 Complete Upper Receiver, AR-15, 5.56x45mm NATO, 14.5 in Mid Length Barrel, 12 in Quad Rail Handguard, No BCG/CH, Magpul Cerakote, Flat Dark Earth, APAR640232Q5

Bravo Company MFG Bravo Company AR-15/M4 Complete Upper Receiver Assembly, Flattop, Aluminum, Black, BCM4-UR-M4

Aero Precision M4E1 Complete Upper Receiver, AR-15, 10.5 in Rifle Length Barrel, 9 in M-LOK Handguard, No BCH/CH, Magpul Cerakote, Flat Dark Earth, APAR640222M2

Aero Precision AR15 Complete Upper Receiver, 16in 5.56 Carbine Barrel W/ Pinned Front Sight Base, M4 Handguard, Black, APAR505621

Luth-AR Complete Upper Receiver Assembly, .223, 31In, 24In, Bull, Rifle, 1X9, 1/2X28, Picatinny, Key MOD, A2 Flash Hider, Anodized, Manganese Phosphate, Silver/ Black, FTBL-B24

Moriarti AR-15 5.56 Nato M4 Carbine Diamond Cut 12in Mlok Upper Assembly, A2, Black, 16In, MAR-5.56-16-12-M4

Stag Arms AR-10 Stag 10 Upper Receiver, Assembly, .210 DPMS High Profile, Left Hand, Type 3 Hard Coat Anodized, Black, STAG310044

Stag Arms AR-15 A3 Flattop Upper Receiver Assembly, Direct Impingement, Type 3 Hard Coat Anodized, Right Hand, Black, STAG300412

Guntec USA AR-15 Complete 5.56 Upper Receiver W/O Lower Parts Kit, N.6, 15in Air-Lok M-Lok Handguard, MLS Gen 2 Stock Assembly, Carbine Length, .750 Gas Block, 16in 5.56mm M4 4150 Barrel, 1-7 Twist, 1

American Tactical Imports AR-15 Complete Upper, 450 Bushmaster, 16in Barrel, Parkerized 15in Keymod Rail, Black, ATI15MS450BM

Aero Precision M4E1 Complete Upper Receiver, AR-15, 5.56x45mm NATO, 16 in Mid Length Barrel, 12 in Quad Rail Handguard, No BCG/CH, Anodized, Black, APAR640231Q7

Tiger Rock Complete Upper Receiver, AR-15, 5.56 NATO, 10in Carbine Length, 1-8 Twist W/ 10in M-LOK Handguard, Black, Large, UB15-P10-10ML

Aero Precision M4E1 Complete Upper Receiver, AR-15, 10.5 in Rifle Length Barrel, 9 in M-LOK Handguard, No BCH/CH, Anodized, Black, APAR640221M2

CMMG Mk4/AR15 Upper Receiver Assembly, Midnight Bronze, 55BA290-MB

Stag Arms AR-15 Tactical Upper Receiver, 5.56x45mm NATO, 16in Barrel, Maryland Compliant, Hanson Profile, 1-7 Twist, 1/2X28, Left Hand, VG6 Delta, Nitride, Black, STAG15110146