In the 1960s, development of a series of projects for tanks with experimental firepower enhancement systems was ongoing. The Federal Office for Military Technology and Procurement was considering the heavily armored Kampfpanzer 67 project, which called for using a fuze programmer and additional firing chambers, as well as potentially combining them. Additional chambers had already been in development for more than one decade by that time, and a fuze programmer was considered a promising direction; however, the appearance of new anti-tank weapons and high development costs compared to the Leopard 1 led to the project's closure at an early stage.