Experimental Primer Seating-Stamping Tool Study in Small Caliber Cartridge Production

Abstract

In an effort to produce a more secure assembly fit between the primer and the cartridge case in 5.56 mm combat ammunition, variants of the conventional case stamping tool were developed and incorporated in the small caliber ammunition manufacturing process (or SCAMP). The challenge is to develop a tool that provides a secure cartridge case-primer assembly fit while maximizing tool life. Two concept tool designs were realized—a concept four-prong triangular stamping tool and a concept four-prong wave stamping tool. This work compares the results of SCAMP trials using a concept four-prong triangular stamping tool, a concept four-prong wave stamping tool and the conventional circular stamping tool. Comparison data include cartridge case material movement after stamping, stamping tool stress distribution, stamping tool life, and stamping forces required to achieve the objective primer seating depths. Although the SCAMP trials are still ongoing, the findings to date show that the wave stamping tool has consistently met the design challenges of improved cartridge case-primer assembly fit and maximized tool life and is currently the leading candidate for implementation in SCAMP.