5.56x45mm NATO Upper Receivers

11.5" 5.56 Carbine Classic Series w/ FSB AR15 Complete Upper (No Handguard)

16" 5.56 Government Midlength Modern Series w/FSB AR15 Complete Upper (No Handguard)

14.5" 5.56 M4 Carbine Modern Series w/FSB AR15 Complete Upper (No Handguard)

Colt LE6920 5.56 M4 Upper Receiver Assembly - No HG's

Colt LE6945 CQB 5.56 Monolithic Upper Receiver Assembly

Colt LE6933-EPR 5.56 M4 Commando Upper Receiver Assembly

10.3 Carbine 5.56 Government M-LOK Upper Assembly

Lantac AR-15 Raven Billet Builder Set - 10.5"

Centurion Arms C4 5.56 Billet AR-15 Receiver Set

NBS 20" 5.56 Rifle Quad Rail Upper Assembly

NBS 20" 5.56 Rifle M-LOK Upper Assembly

NBS 16" 5.56 Left Handed Complete Upper

Dirty Bird 10.5 Government Carbine 5.56 M-LOK Upper Assembly - V3, Midnight Bronze

Dirty Bird 10.5 Government Carbine 5.56 M-LOK Upper Assembly - V2, Midnight Bronze

Dirty Bird 10.5 Government Carbine 5.56 M-LOK Upper Assembly - V2, OD Green

Dirty Bird 10.5 Government Carbine 5.56 M-LOK Upper Assembly - V2, FDE

Dirty Bird 16" 5.56 NATO Govt M-LOK Upper Assembly V3 - FDE

Dirty Bird 16" Govt Mid 556 M-LOK Complete Upper - FDE

Aero Precision M4E1 Enhanced Upper Receiver and M-LOK Handguard Combo Gen 2 - Anodized Black - 15"

NBS 14.5" (16" Overall) Mid-Length 5.56 NATO 1:7 Complete Upper w/ FSB and Pinned/Welded VG6 Precision Epsilon Muzzle Brake

NBS 16" Carbine 5.56 NATO 1:7 Complete Upper

Stag Arms 16" 15 L Tactical M-LOK/Quad Rail Midlength Left-Handed Upper Assembly - CA Compliant

Stag Arms 16" 15 L Tactical M-LOK Midlength Left-Handed Complete Upper-CA Compliant

Spikes Tactical Gadsden Lower/Upper Combo Gold .223 Rem / 5.56 NATO