Al_Qeasies were probably using 7.62x39, alhtough 5.45x39 is possible. The former is lighter and slower than 7.62Nato, while the latter is lighter but faster and has less area. It might be a harder round to stop. But the older AK-47 round is more likely, since the AKs are everywhere and there is plenty of the ammunition about..I've even got some, but then I've got more 7.62NATO, Portuguese mostly. Binny Boy's Krinkov, a stubby AK type, probably is 5.45x39