I've purchased surplus ammo before from some countries and had amazing success. There has been a lot of Ethiopian ammo appearing again and a good example of the quality, or lack of quality control, in this ammunition.
"During testing, both the 7.92 and 7.62 cartridges exhibited hang-fires in approximately fifty per cent of cases."
http://armamentresearch.com/ethiopia...7mcDtTaqjoBPX4