Three versions of the "C model" were built.

The C model had a fixed stepping system with a large wheel cycle due to the prime numbers of the six wheels.

These were the only "C" models ever exported, even as second-hand examples.

Immediately upon their return, they upgraded to C model Hornets.

The D-0 was similar to the earlier C models, with a few notable changes.

C models were deployed between 1976 and 1981, reaching operational status in 1978.

Development on the "C" model had commenced in 1960, with production starting in June 1966.

It has the larger hopper of the "C" model.

By this point the Army had become more interested in the design, and asked Allison to continue with a new "C" model.