Very Tiny Gun

All of 13 millimetres long.

15mm German WWII Grenadier by Battlefront

Here's the 1:100 scale (15mm) Lewis Gun I had printed in FED resin by Shapeways.

The FED really does render pretty decent detail, and though it is more expensive than FUD, for this sprue of six Lewis Guns and pole-mounts, the difference was only a buck or so.

The trouble with modeling personal weapons for wargames figures is illustrated in the photo of the gun next to a WWII German Grenadier. To suit the figures it really needs to be modeled a bit bigger and a lot more chunky. In true 1:100 scale, it looks far too light and slender next to the figure; more like the proportions of a rifle.

That's something that can really only be determined by trial and error; you just have to find out what looks right with the figures you have.

I may do another sprue of guns in rather more exaggerated proportions for this very reason.