Case box, 5.56mm is a type of miscellaneous item in Fallout: New Vegas.
Characteristics
Case boxes contain cases used in crafting the type of ammunition on their label. Each box contains 25 case, 5.56mm.
Uses
Ammunition casings are used in the crafting of ammunition at reloading benches. Combine (1) case, 5.56mm, (12) lead, (4) powder, rifle, and (1) primer, small rifle to get (1) 5.56mm round.