Panzer Arms M4 Tactical Barrel Assembly Nickel 5.56 NATO

TacFire AR-15 Blow Back .45 ACP 1:16 4140 Chrome Moly Steel Barrel - 5/8x24 - 7.5"

Faxon Firearms Carbine-Length Button Rifled Pencil Barrel w/Pinned Gas Block 5.56x45mm 10.50", Black

Sons Of Liberty Gun Works M4-L89-13.7 M4-L89 5.56mm 30+1 13.70" Black QPQ Button Rifled Barrel, Black Hardcoat Anodize Receiver, Ambidextrous

Lead & Steel Llc LS556PEN-CAR-16 5.56mm 16 Pencil Profile Features M4 Feed Ramps Carbine-Length

TacFire AR-15 Blow Back 9mm 1:10 4150 Chrome Moly Vanadium Barrel - 1/2x36 - 4.5"

Faxon Firearms Mid-Length Button Rifled Pencil Barrel 5.56x45mm 16", Black

FN America AR-15 16" Barrel 556NATO 1:7 Twist Button Broached, Black - 20100039