GC_UPC Bushmaster XM-15 Complete 5.56x45mm Upper Receiver 16" Barrel - 00-400003-BLK $449.99 00-400003-BLK show more like this Calculated in Cart Classic Firearms GC_UPC Bushmaster Complete Quick Response Carbine Upper - 16" Upper 5.56 NATO - QRC | With BCG & CH $530.00 00-40003-BLK show more like this Right To Bear