MTM's rifle ammo boxes feature a flip-top with rounded edges are made of polypropylene plastic that will not warp, crack, chip , peel, expand or contract. Designed for the short magnum and large ultra magnum rifle calibers, they hold 22 rounds.Your ammunition will stay safe and dry in these 22 round flip top ammo boxes made from polypropylene. They are designed for the new short magnums and the large ultra magnums and will not warp, crack, chip, peel, expand or contract.