%0 Journal Article %A Ritter, John J. %D 2013 %I Begell House %K small caliber, ignition, 5.56 mm, interior ballistics, primer performance %N 4 %P 361-370 %R 10.1615/IntJEnergeticMaterialsChemProp.2013005291 %T CHARACTERIZING 5.56-mm CARTRIDGE PERFORMANCE WITH NOVEL MEASUREMENT TECHNIQUES %U https://www.dl.begellhouse.com/journals/17bbb47e377ce023,666ac2715cb41467,411050064d137a4e.html %V 12 %X A custom, in-house designed breech for an M16A1 Mann barrel, 5.56 mm, has been instrumented to measure the force output of an unsupported primer. In addition, the Mann barrel is designed to accept gauges at two diametrically opposed locations to simultaneously measure mid-case chamber pressure. This one-of-a-kind apparatus provides an advanced diagnostic tool to gain insight into the interactions between the primer and propellant bed of the 5.56-mm cartridge during ignition, and allows for enhanced characterization and understanding of the cartridge's interior ballistics. The experiments performed investigate the role of the primer, cartridge temperature conditioning, and charge weights in their respective effects on chamber pressures and primer forces. The results indicate the primer force measurement is an invaluable tool in evaluating the interior ballistics of the 5.56-mm cartridge and it provides information that the more standard mid-case or case-mouth pressure techniques overlook. This pioneering system-level approach provides detail into the primer/propellant interactions never before observed by analyzing the primer and propellant outputs simultaneously within a closed system. In addition, this diagnostic technique provides further early time data. It advances the initial data acquisition timeframe to when the firing pin strikes the primer, whereas previous diagnostic techniques began when the propellant gas generation is first recorded. The additional data gained through the primer force measurement provide investigators a new avenue into malfunction investigations, as well as giving formulators and designers an additional tool to characterize the performance of new primer and/or propellant formulations in search of the optimized weapon cartridge. %8 2013-09-26