M919 Cartridge 25mm, Armor Piercing, Fin Stabilized, Discarding Sabot, with Tracer (APFSDS-T)
The 25mm Armor-Piercing, Fin Stabilized Discarding Sabot with tracer (APFSDS-T) M919 has been designed and developed to replace the currently fielded M791 cartridge as the service armor piercing round for the Bradley. The M919 uses a high length/diameter ratio, depleted uranium penetrator and high energy propellant to achieve improved terminal ballistic characteristics.
This round is a fixed type, percussion primed round consisting of a sabot encapsulated projectile body crimped to a steel cartridge case. The projectile body consists of a depleted uranium penetrator, pressed on aluminum windscreen, screw on fins with pressed in tracer pellets, segmented discarding type nylon sabot, and pressed on polyethylene nose cap. Gases produced by the burning propellant discharge the projectile from the gun at 1,420 meters per second (plus or minus 20 meters per second) and ignite the tracer. Setback, centrifugal force, and air pressure cause the sabot to discard on leaving the gun barrel. The discarding sabot leaves the barrel at a 17 degree angle on both sides of the gun target line for 100 meters (total of 34 degrees). The tungsten penetrator with a depleted uranium core is fin stabilized and penetrates the target solely by kinetic energy.
Currently in production, the M919 Brings modern kinetic energy round technology to the Bradley Infantry fighting vehicle. It defeats a higher class of threat infantry fighting vehicle at greater range than to the M791 APDS-T cartridge. Its advanced armor defeat mechanism, combined with a high muzzle velocity yields a very high kill probability for firing at stationary and moving targets. The M919 round uses state-of-the-art technology by incorporating high energy propellants, low drag design, an aluminum sabot and an improved depleted uranium penetrator material
The System Contractor is General Dynamics Ordnance & Tactical Systems (GDOTS).
The new 25mm Armor-Piercing, Fin Stabilized, Discarding Sabot with Tracer (APFSDS-T), M919 Cartridge is intended to supplement the currently fielded Armor Piercing M791 as the primary service round. This action modernizes the war research of the Army 25mm armor piercing ammunition for use in the Bradley Fighting Vehicle. The M919 was designed and developed to increase the lethality of the BFV by extending its defeat range capability against projected target threats of the 1990s and beyond. Not only does this munition enhance the soldier's lethality and survivability, but, also significantly contributes to the overall Army's mission.
In the mid-1980s, the Army determined that the then current armor piercing round in U.S. inventory could not defeat the postulated future light armored vehicle threat of the 1990s. In 1986, the Office of the Deputy Chief of Staff for Logistics approved the requirement for an extended range, more lethal armor piercing round. Early design efforts had focused on a tungsten long rod but testing determined that it was incapable of delivering the required level of performance. The decision was made to pursue a depleted uranium long rod for use in the Bradley Fighting Vehicle.
The M919 simultaneously completed its FY90 limited production while initiating its first full rate production contract (FY91S). There were two additional full rate production contracts pending, a $22.5M FY94 and $29.5M FY95 procurement, both of which were awarded in Calendar Year 1995. All contracts have been (up through the FY95 award) awarded to Olin Ordnance under a sole source firm fixed price basis. All procurements are made based form, fit, and function (i.e., ctg top level drawing, weapon interface drawing, and a performance SPEC). On 12 September 1996 TACOM Commander Maj. Gen. Edward Andrews approved the initial Material Release of the M919.
Referred to by the user as the Super Sabot Kinetic Energy Dart, the M919 was designed to defeat all current enemy light armor of the 1990s at extended ranges through a combination of high on-target strike velocity and improved penetrator geometry and material. Thus, the M919 effectively enhances the lethality and survivability of the BFV without modifying the weapon system. While the effective range of the M919 remains classified, the maximum range of this round is about 17,600 meters. These figures translate into greater crew protection and survivability to move onto the next battle.
In a technological innovation, the barrel life of the M919 was tremendously extended with the use of a blended propellant and a grease paste erosion inhibitor. At high rates of fire, the original M919 had a barrel life of less than 300 round. A team of scientists specializing in barrel heating and erosion from CCAC, AED, Benet Labs, Aerojet and Veritay Technologies conducted an 18-month development program using a 10,000 round, multi-barrel test to verify ARDEC's claim that the M919's barrel life had been enhanced to over 5,000 rounds.
Hazard classification testing was conducted in 1988 at Nellis Air Force Base. Environmental sampling showed no indication that DU oxide had become airborne during the burn test (setting a pallet of ammo on fire). Essentially all of the oxide produced was insoluble when analyzed using a simulated lung fluid test. Only 0.1 to 0.2 percent of the oxide was small enough to be inhaled.
Radiological assessment of the M919 cartridge for external radiation levels was conducted in 1989. The components of the M919 effectively shielded out the predominant alpha and beta radiation. The gamma radiation penetrated the projectiles and the shipping containers. The highest radiation measurement was at the center of the shipping container. Radiation levels at the surface of a single shipping container, measured with field use exposure rate instruments, had a maximum reading of 0.6 mR/Hr. This exceeds the surface exposure rate criteria of 0.5 mR/Hr for excepted material. All other criteria are satisfied by the M919 shipping package.
The Army's M919 ammunition DU cartridges are packaged in plastic (M-621) and metal (PA-125) shipping containers and the Marine Corps's metal (CNU-405) container. The radiation levels associated with the M919 are low and do not significantly endanger personnel handling and storing the ammunition. The radiation levels in the Bradley M3A1 and the LAV-25 also are low. Potential doses to personnel in these vehicles will depend on the duration of occupancy in the vehicle and the configuration of the stored munitions.
The components of the M919 effectively shield out the predominant non-penetrating radiation emitted from the bare penetrator and significantly reduce the majority of the penetrating photon energy. The 1.0 MeV photons resulting from the decay of 234mPa can penetrate both the components of the projectile and the plastic M-621 and metal shipping containers but are attenuated by the components.
Radiation levels at the surface of the single shipping container and the pallet of 27 shipping containers, measured with field-exposure-rate instruments, do not exceed 2.5 mR/h. The exposure rate is well within the US Department of Transportation's (DOT) special exemption of 2.5 mR/h limit for DU munitions. Therefore, if the Army obtains approval from the Military Traffic Management Command (MTMC), the XM919 shipping container may be shipped under DOT exemption DOT-E96-49. Otherwise, the containers must be shipped under the provisions of 49 CFR 173.425 entitled "Transport Requirements for Low Specific Activity (LSA)." The Hazard Classification Tests performed on the XM919 included the Stack Test, which evaluates detonation propagation, and the External Fire Stack Test, which evaluates the cartridges' explosiveness and fragmentation resulting from setting fire to boxes of cartridges. In addition, the M919 was tested against hard armor and wood/masonry targets to determine the extent and nature of DU aerosols created. There was no propagation of initiation demonstrated from the Stack Test. The effects of initiation of the donor cartridge were limited to the donor container. There was no propagation of initiation to the other shipping containers. There was no mass detonation of the cartridges. The cartridges exploded progressively and the effects were limited to the immediate test area. There were some signs of oxidation on many of the penetrators that remained in the fire. Approximately 35% of the total DU used in the External Fire Stack Test was oxidized. Between 0.1% and 0.2% of the oxide was within the respirable range. The lung solubility analysis of the DU oxide determined that 92.6% was insoluble and 6.8% was slightly soluble. There was no indication that any measurable DU became airborne as a result of the External Fire Stack Test. There was less than 10 % of DU made airborne from the hard target impact testing. Less than 0.1% of the initial DU penetrator weight was within the respirable size range. About 17% of the oxide present in the smallest size fraction was soluble while the remaining 83% was insoluble.
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