Striker

Striker, and Striker II I believe, are the mass combat SG2/DS2 of the
Traveller (early to mid generation) universe. They have (if you read the
fluff) a very GZGesque feel too them. They were often played in
15mm (given the Martian Metals 15mm Traveller figs and 1/72
scratchbuilt vehicles). A not-bad system which captured the flavour of
the Traveller universe. And the vehicle construction rules, though quite
complex... (oooh boy... want to build every component including weapons?)...
produced some quite interesting and fun results.

A good system. Jon built something very similar flavour wise, but with less
overhead.