If you're in the market, Midway has these mags in stock...
Command Arms Mag AR-15 223 Remington 30-Round Polymer Black
AR-Stoner Mag AR-15 223 Remington 30-Round Curved Body Anti Tilt
Command Arms Mag AR-15 223 Remington 30-Round Polymer Black
AR-Stoner Mag AR-15 223 Remington 30-Round Curved Body Anti Tilt