
156 Ballistics: Theory and Design of Guns and Ammunition
Equations 4.142 and 4.143 now contain only two unknowns, r and F. The procedure now
involves solving both Equations 4.142 and 4.143 and plotting the force, F versus r. The low-
est value in either equation is then the force (and location) at which the joint will fail. It is
recommended that these solutions be performed with the aid of a computerized numerical
calculation program such as MathCAD.
Partial threads can have a signicant effect on the failure strength of a joint. If the joint
were designed to survive, it is generally best to ignore the additional strength afforded by
partial t ...