Carbines eat, and this shelf is built for it: M193 55 grain and M855 62 grain 5.56 NATO by the box and the case, alongside duty-grade barrier loads and heavier match offerings for precision ARs. Case pricing rewards buying practice ammo the way you actually shoot it.
Remember the chamber rule: 5.56 runs safely in 5.56 and Wylde chambers; rifles marked .223 Rem only should stay on the .223 shelf. Check your barrel stamp before you stock up.