A General Purpose Prototype Muffler for the Bradley Fighting Vehicle 25-mm Automatic Cannon

In response to noise problems in Germany incurred by the Bradley Fighting Vehicle BFV 25-mm M242 Chain Gun, two prototype mufflers for use with all types of ammunition were designed, fabricated, and performance-tested against requirements given by an Operational Needs Statement One muffler is used with a standard barrel while the other muffler requires a unique perforated barrel. Tests included noise attenuation, toxic fume concentrations within the BFV, and projectile dispersion. Noise requirements were met and even exceeded by the muffler that requires perforated barrel. Subsequent testing was performed with the perforated barrelmuffler system. With a modified ventilation scheme, the most severe training scenario could be run three times in succession without exceeding the maximum permissible toxic levels of the relevant MIL standard. Moreover, the visible smoke was removed from the BFV interior and there was no eye irritation. It is recommended that this ventilating scheme could be used with the muffler. Dispersion testing of M793, M791, and M910 ammunition, when firing both stationary and on the move, resulted in the barrelmuffler system performing as well as or better than the standard barrelbrake system in five of the six events. However, more testing is needed to draw statistically firm conclusions. For this particular muffler, noticeable erosion occurred in the material around the exit hole. For future mufflers, implementation of a small design change should eliminate any erosion problems.