Bushmaster IV

The Bushmaster IV is a 40 mm chain-driven autocannon designed and built by Alliant Techsystems, based on the M242 Bushmaster, Bushmaster II and Bushmaster III. The Bushmaster IV fires 40×365mmR 3P (Prefragmented, Programmable, Proximity-fuzed), APFSDS-T Mk I, and APFSDS-T Mk II rounds. The 3P round will provide air burst capability and the APFSDS-T Mk II can penetrate armor with a thickness in excess of 150 millimeters.

Specifications
The Bushmaster IV requires 5 hp at 24 volts to operate, fires from a cook off safe open bolt with absolute hangfire protection, and ejects forwards. It fires NATO standard 40×365mm ammunition from an integral linkless feed and has a recoil force of 62272 N. The ammunition was originally developed for the Bofors 40mm L/70 cannon.