5.56x45mm NATO Upper Receivers

Rainier Arms RUC Pro MK2 5.56 NATO Partial Upper Receiver

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 14.5" FDE

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 12.5"

Rainier Arms RUC PRO MK1 5.56 NATO Partial Upper Receiver - 10.5"

Rainier Arms RUC DI 5.56 NATO Partial Upper Receiver

PSA 20" CHF Rifle Length 5.56 NATO 1:7 Premium Rifle Kit - 8818

PSA 16" Nitride 1:7 M4 Carbine 5.56 NATO MOE AR-15 Upper Assembly, Black - With Rear Mbus No BCG/CH

PSA 14.7" Mid-length CHF 5.56 NATO 1:7 13.5" Lightweight M-Lok Upper Pinned & Welded - No BCG or CH - 77932796

PSA 7" Nitride 1:7 Pistol Length 5.56 NATO Marauder AR-15 Upper Assembly, Black - No BCG/CH

PSA 20" Rifle Length 5.56 NATO 1/7 Nitride Freedom Rifle Kit - 7788893

PSA 16" Mid-length 5.56 NATO 1:7 Nitride MOE Freedom Upper - Without BCG / CH - 7780446

PSA 16" Midlength 5.56 NATO 1:7 Nitride MOE Freedom Rifle Kit - 7780444

PSA 16" Classic M4 Freedom Upper with BCG & Charging Handle, OD Green

PSA 16" Carbine Length 5.56 NATO Classic Freedom M4 Upper w/ BCG and CH, Flat Dark Earth - 7779344

PSA 16" Classic M4 Freedom Upper with BCG and Charging Handle

PSA AR-15 Upper 5.56 16" 1:7 Socom Nitride 13.5" Lightweight M-Lok w/NiBx BCG, CH, & MBUS Sight Set

PSA "Sabre" Forged 13.7" FN CHF CL Mid-Length 5.56 with 13" Sabre Lock Up Rail and JMAC GFHC-E Pin and Weld

PSA "Sabre" Forged 13.7" FN CHF CL Mid-Length 5.56 with 13" Sabre QD Rail and JMAC GFHC-E Pin and Weld

PSA "Sabre" Forged 13.7" FN CHF CL Mid-Length 5.56 FSB with 13" Two-Piece Quad Rail and JMAC GFHC-E Pin and weld

PSA "Sabre" Forged 13.7" FN CHF CL Mid-Length 5.56 with 13" Quad Rail and JMAC GFHC-E Pin and weld

PSA "Sabre" Forged 16" 5.56 Nitride 13" Sabre QD Rail with Sabre Compensator

Blem PSA AR-15 Complete Upper Receiver

PSA 16" Classic M4 Freedom Upper No BCG & Charging Handle, OD Green