Patent ID: 7607392

Claim:
A shellcase body for use as part of an ammunition cartridge, comprising: a base portion having proximate thereto a point of origin from which primer explosion is initiated; a middle portion joined with said base portion, said base portion and said middle portion being arranged around a center longitudinal axis; a shoulder portion having a curvature that is defined by a circle having a predetermined radius and a center that is positioned a distance away from said center longitudinal axis, wherein said shoulder portion is joined with said middle portion at a secant point of said circle and extends therefrom to form an open end, said radius and center defining an interior surface having an angular orientation relative to said point of origin that is effective for redirecting substantially all shock waves originating from said point of origin away from said open end of said shoulder, to thereby reduce the risk of a projectile associated with said open end from becoming prematurely dislodged as a result of shockwaves.