13965

Title: .30 Caliber Blank Function and Safety Testing Abstract Text: The Caliber .30 M1909 blanks are used by veteran organizations to render funeral honors in the .30 Caliber M1 Garand rifle. The U.S. Army manufacturers the M1909 blanks and provides them to the veterans at no cost to the users. The Caliber .30, M1909 Blank Cartridge was redesigned in January 1999 after almost 30 years without significant changes. The ammunition was changed from a bottlenose style that used wadding to seal the cartridge to a rosette crimp type. This change was to keep pace with the current manufacturing standards for the manufacture of blank rounds. The propellant was changed from an obsolete propellant to the more commercially available propellant used in the M200 5.56 mm blank cartridge Reported problems with the blanks have been increasing since the redesign in January 1999. The propellant change was considered to be the cause of some of the problems. Around the same time the primary U.S. based ammunition plant was not able to produce the M1909. They outsourced the production and the 5.56mm propellant requirement was waived as long as the M1909 met the performance standards. These standards essentially only measured the sound level and ability for the weapon to cycle. Since the redesign and outsource frequent problems have occurred with the M1909 .30 Caliber blank. The most common problem that occurs is the weapon fails to feed the next cartridge. More severe problems involve the blank firing adapter (BFA) dislodging and essentially becoming a projectile. Blank firing adapters have also ruptured as a result from firing the M1909 blanks. There was one instance in which a M1 Garand rifle receiver experienced a structural failure which resulted in the user experiencing a deep laceration to the face. This failure launched the investigation of the blank ammunition. The objective was to determine whether the weapon or the ammunition was the cause of the failures described above. Testing was conducted in both the M1 Garand rifle and a test barrel. The M1 rifle was outfitted with a pressure transducer in the gas plug to measure the port pressure. The test barrel had pressure transducers at both the case mouth and at the same distance that the port is located on the M1 rifle. The bolt velocity on the M1 rifle was recorded using a high speed camera. Three different ammunition types were used. The U.S. manufactured .30 caliber blanks, the outsourced .30 caliber blanks, and .30 caliber M2 ball ammunition. The blank firing adapter orifice was drilled out to six different sizes to determine the influence on pressure and bolt velocity as well as to determine if the currently recommended size was optimal. Four different weapon orientation angles were used during testing to determine the effect on pressure and bolt velocities. Since blank ammunition has a large amount of ullage compared to ball cartridges, the orientation causes the propellant to settle differently throughout the case. This has a large effect on the internal pressures of the weapon system. The testing was able to recreate the failure of a M1 Garand receiver that was experienced in the field. Extensive data was collected on the behavior of the propellant gasses inside the weapon systems. It is not believed that this data on blank internal ballistics was available prior to the testing being conducted. The data allowed the engineers to determine the cause of the weapon failures and to relay this information to the user community. The blank ammunition was found to not be at fault and the cause of the failures was determined to be a combination of user error and lack of maintenance and service to the rifles. This information was relayed to the organization that provides M1 Garand rifles to the veterans and they agreed with the results of the testing.