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M865 TPCSDS-T 120mm Cartridge

Training ammunition is used to provide a realistic simulation of tank cannon ammunition in a controlled environment in terms of safety, range, and cost. The M865 is the current U.S. Army 120-mm kinetic energy projectile training ammunition. The 120mm M865 Target Practice, Cone Stabilized, Discarding Sabot - Tracer (TPCSDS-T) cartridge is a range limited kenetic energy (KE) type training cartridge. It was a direct technology transfer from the German model DM38, but has been significantly modified from that configuration. Major changes include use of M14 propellant (versus LKL), propellant containment bag, short sabot, and an aluminum slotted conical fin. The M865 utilizes a slotted tail cone which limits the subprojectile range to a maximum of 8000 meters at 10 degrees elevation. In addition to limiting range, the tail cone provides stabilization for the steel subcaliber projectile. The M865 propulsion system is the same as the M829 except that the M865 utilizes a single-base solvent type propellant. The major components of the M865 are:

  • M865 Projectile
  • Combustible Cartridge Case /Case Base & Seal Assembly
  • M125 Primer
  • M14 Propellant, Single Base
  • Tracer

The 120mm M865E2 is a Target Practice, Fin Stabilized, Discarding Sabot - Tracer (TPFSDS-T) cartridge, produced through means of recovery of M829 cartridges and converting to a training cartridge. The M865E2 is functionally indistinguishable from the standard M865 in that it is a kinetic energy training cartridge. The major components are:

  • M865E2 Projectile
  • Combustible Cartridge Case w/Case Base & Seal Assembly
  • M125 Primer
  • M1 Propellant
  • Tracer

The M865E2 TPCSDS-T Cartridge is intended to supplement production of the M865 TPCSDS-T target practice training cartridge. The objective of the program is to produce a cartridge that performs as well as and costs no more than a new M865 cartridge. This objective is achieved by reutilizing components from M829 APFSDS-T cartridges and reutilizing M1 propellant from Army surplus M4A2 artillery charges. In addition, most of the components are reutilized as a unit as opposed to individual components, thus avoiding the cost and effort of assembly. The remaining components to be manufactured to complete the M865E2 Cartridge are minor modifications of existing tank ammunition components. Production of this cartridge will be limited. The scheduled buy for this effort is 65,000 cartridges over a three-year period (15,000 the first year, 25,000 the second and third years). The number of M829 Cartridges in existence limits the maximum possible number of M865E2 Cartridges that could be produced. Program benefits include removing unneeded tactical cartridges and propellant from the Army inventory (avoiding storage and maintenance costs), and producing high-quality yet low-cost tank training ammunition.

On 29 July 2002 (0031 hours), during standard night field training at Fort Hood, an M1A2 SEP Abrams Main Battle Tank (6312) erupted in fire killing the driver and the loader (C Company, 3-67 Armor Battalion, 4th Infantry Division.) At the time the tank crew had just completed a Table VII, Task B2 Defense training exercise with the firing of three M865 kinetic energy training rounds. On 31 July 2002 an Accident Investigation Board (AIB) presided over by LTC Joseph Sette (from the Army Safety Board at Ft Rucker, AL ) was formed to gather and evaluate evidence which caused or contributed to the accident and recommend actions which will prevent future accidents. The last incident of this type happened 13 years ago. The cause was identified as cartridge dropped on hot primer in spent case base initiated cartridge.

Subsequently, a root cause analysis completed by TACOM-ARDEC, which concluded that power from a damaged door safety switch initiated a cartridge which was not properly stowed in the ready rack. As a result of the lack of testing and some susceptibility to cell phone and SINCGARS radio emissions, ARDEC initiated a test program to eliminate any concerns about these devices (no cell phones found in tank). A primer redesign effort was begun to reduce electromagnetic sensitivity of the primer as well as improve producibility.

Cartridge, 120mm, Form Fit & Function (F3), M865

The 120mm M865 Form Fit & Function (F3) Cartridge is a Target Practice, Cone Stabilized, Discarding Sabot - Tracer (TPCSDS-T) cartridge, produced to a Performance Specification rather than to a standard government technical data package (TDP). The F3 M865 is functionally indistinguishable from the standard M865 in that it is a range limited, kinetic energy, training cartridge, however, the actual configuration is unique to the individual producer, responsible for his individual design. The major components are:

  • M865 F3 Projectile
  • Combustible Cartridge Case w/Case Base & Seal Assembly
  • Primer
  • Propellant
  • Tracer

The steel core of the M865 has substantial potential for producing lethal damage in the event of a training accident. Researchers at the U.S. Army Research Laboratory recently conducted a combined computational and ballistic firing program to design and evaluate a 120-mm training round for mitigating lethal damage in the event of a training accident.

Large-scale simulations were an integral part of the design and analysis of a hollow aluminum training round (HATR). Eulerian finite-difference simulations were used to model the HATR subjected to the high rate loading and large deformations encountered during impact.

Performance of the HATR was measured in terms of depth of penetration into rolled homoge- neous armor (RHA) at typical ordnance velocities. The HATR simulations predicted an order-of-magnitude reduction in penetration compared to the M865 over a broad range of striking velocities. The figure shows a typical HATR simulation at impact and at 340 1ls after impact.

Ballistic firings and large-scale simulations have demonstrated a concept for reducing the potential lethal damage of large-caliber training ammunition by an order of magnitude. In addition, prelimi- nary cost analyses estimate a 5% reduction in materials and manufacturing costs for the HATR compared to the M865. Considering the large quantity of tank cannon training ammunition procured each year by the U.S. Army, this represents a significant cost reduction.

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Page last modified: 07-07-2011 02:52:21 ZULU