Using 5.56 ammo in an AR-15 that only takes .223 could be one of the most expensive mistakes you make. For many shooters, this causes extra time to be spent at the range to properly identify which magazine holds which ammunition. Rather than go through this hassle, it helps to have an identification system in place. Hexmag HexID Blackout Mag Follower is the perfect way to make your magazine more distinct and provide for ammo identification at a glance.
You may decide to load one mag with the 300 BLK round while another holds the 5.56 ammo for target practice. This blackout follower will be the perfect way to know what type of round you have loaded in the magazine. If you use other variety, try adding other colors as well to further distinguish from one mag to another.