Next-Gen 120mm Tank Killer: ATK’s M829E4 AKEJul 13, 2011 16:49 UTC by Defense Industry Daily staff
ATK recently announced a $77 million, 3-year contract, exercising an option to develop and qualify the USA’s new 120mm tank-killing round for use in the U.S. Army’s M1A2 SEP Abrams tanks. The M829E4 is called the Advanced Kinetic Energy round, and belongs to a class known as APFSDS-T: Armor Piercing, Fin Stabilized, Discarding Sabot with Tracer. As the picture shows, the shell casing releases a penetrator sabot dart, which flies at extreme velocity to punch through enemy tank armor. The tracer element makes it easy to see the round in flight.
While manufacturers like Rheinmetall use tungsten alloys for the APFSDS dart, American rounds use alloys of similarly-dense depleted uranium (DU)…
Stable DU alloys are manufactured and machined by the USA’s National Technology Industrial Base (NTIB), and the penetrators are given to firms like ATK, which is then responsible for the surrounding cartridge. The penetrators are mostly Uranium-238, with varying amounts of metals like titanium mixed in, depending on the required function.
Depleted Uranium’s density, and sharply lowered U235 content, has led to its use in applications like radiation shielding and tank armor. The same American M1A2-SEP tanks that will fire DU alloy shells also include DU in their armor’s series of layered materials, creating more protection than the same thickness of homogeneous rolled steel. When used in a sabot round, DU alloys are self-sharpening and slightly incendiary, making them an excellent choice. DU has some health controversies associated with it. On the other hand, its tungsten alloy alternatives may not be any safer.
To reach the single manufacturer Engineering, Manufacture and Development (EMD) Phase I, ATK’s round had to pass a shoot-off. This is the EMD Phase II contract. It would be followed by Low Rate Initial Production of 640-960 rounds, then options for up to 2 years of Full Rate Production of 3,360 – 5,040 per year. FBO.gov | ATK.