I use a basic "dark gun metal" mix made from Vallejo "Rubber" (a very dark bluish-black gray) and Citadel "Boltgun" (a rather bright gun metal).
I highlight the edges and other details with Citadel "Boltgun," "Chainmail," and "Mithrial" silvers which are three different, progressively brighter colors. I try to be a little more selective and logical with this highlighting then just dry-brushing. When doing the highlighting, I also try to emphasize parts of some weapons that might be removed or disassembled often (removable magazines, changeable gun barrels, etc) by either showing more or less wear than on the rest of the gun.
For weapons that were Parkerized, I go over these colors with a wash of Payne's gray oil paint. For weapons that were blued, I use an oil wash made of indigo.
Finally, I give the weapons an overspray with a clear flat like Testor's "Dull Coat."
The Breda MG on this model was painted using these techniques:
![](../../../i380.photobucket.com/albums/oo243/SGM_ret/M13_40---Construction---Photos/Finished12_zpsc21c6f47.jpg)
![](../../../i380.photobucket.com/albums/oo243/SGM_ret/M13_40---Construction---Photos/Finished10_zpse9c3b8db.jpg)
I used a Payne's gray wash on the gun and barrel and an indigo wash on the magazine. I limited the highlighting on the magazine and (removable) gun barrel to contrast those details from the well-worn receiver group.
The full build blog can be found here:
Armorama::M13/40 early - Tamiya & Italeri Kit Bash HTH!