Which "Dirt" are we talking about? Iraq? Afghanistan?
In Iraq, besides the standards you mentioned I've also seen 9mm Mak, .32ACP for the Iraqi Tariq ripoffs of Beretta, and .38 S&W for the Enfield revolvers. For rifles, have found entire crates of milsurp 8mm and Soviet-production 7.62x25mm for the Shpagin buzzguns (PPSh-41, etc.)
Also found rifles in .303, 8x56 Austrian Steyr, and the Czech 7.5x45mm, but never found ammo for them.
But that was a couple years back, and just in Anbar province, so it may vary a lot depending on proximity to bordering countries, local culture, etc.
-MV