Patent ID: 7644662

Claim:
An elastic retention ring for use with a combustible casing of a piece of ammunition that is held in place by a base, the elastic retention ring comprising: an internal substantially ring-shaped portion; an external substantially ring-shaped portion, concentric with the internal substantially ring-shaped portion and having a diameter larger than a diameter of the internal substantially ring-shaped portion; and a plurality of elastic radial arms that link the external substantially ring-shaped portion to the internal substantially ring-shaped portion, wherein the external substantially ring-shaped portion has at least one planar portion contacting a bottom surface of the casing, and the internal substantially ring-shaped portion extending in a plane parallel to the bottom surface of the casing and disposed above the at least one planar portion of the external substantially ring-shaped portion, with the plurality of elastic radial arms connecting the planar portion of the internal substantially ring-shaped portion to the planar portion of the external substantially ring-shaped portion.