A reader passed this on to me:
I saw this and thought of you. Do you have any more info on this? What type of gun is it?
Well, that’s definitely a Heckler & Koch MP5K briefcase gun. The MP5K is the small “commando” version of the popular MP5 and, like its big brother, fires the 9x19mm Parabellum (Luger).
Here’s a video of the briefcase gun in action:
I haven’t heard of insurgents in Iraq using them, but the photo from Military.com shows 3rd Infantry Division troops checking them out, and given the desert BDUs I’d guess this picture is from the initial invasion in 2003 or its immediate aftermath.