Actually the ammunition was imported here in the United States by the Hansen Cartridge Company from Yugoslavia in the 1980's - thus it is very possible to see StG-44's here in the US that would have ammunition. Not as ample as ammo for the Garand, Mauser or other older military rifles - but more than enough to give the owner enough ammo to be a very big pain if all you expected to go up against was shotguns and hunting rifles.
http://www.ar15.com/archive/topic.ht...&f=16&t=570619