I blogged a little while back on cadcam impacts on wargame miniature production. Here is an example from Plastic Soldier. Here are a Russian AT gun and a field gun in two scales, 28 mil and 1/72 (roughly 20 mil). The models are identicalexcept for size; look at the guy with the outstretched hand.. I believe they also do the same miniatures in 15 mil.
Once you have the design sorted any scale can be produced.