F ProMag RollerMag Magazine AR-15 223 Remington, 5.56x45mm, 300 AAC Blackout Polymer - 137895 $16.99 RM-40-OD show more like this 5.00 MidwayUSA F ProMag Polymer Magazine AR-15 223/556mm Olive Drab 40 rd RM-40-OD $31.26 RM-40-OD show more like this lat rate starting at $11.99 Hinterland Outfitters