A container system and method for shipping and storing an item is provided. The container system may comprise a storage vessel with an interior compartment, and an access opening at one end. A removable end cap may be releasably and mechanically coupled to the storage vessel at the access opening, fully enclosing the access opening. Mechanical fasteners may also be secured to the storage vessel and removable end cap to form the releasable, mechanical connection. In one embodiment, at least one stacking lug may be provided at the perimeter of the storage vessel. In another embodiment, the container may comprise a pressure vessel, which may be adapted to receive a round of ammunition.