Just remember that lug setback and increased head space had always been a problem in Enfield .303s thet have been in heavy use. In the MK-3 and MK-4 this was less of a issue but with the 7.62 I would expect this to return. I would not worry as it probably would take enough rounds to wear out the barrel as to wear out the action. This was issued by a peice time army as a temp. measure untill a proper 7.62 gun could be developed. As for the CETME rifle it is chambered in 7.62 cetme and not 7.62 nato, performance is similar to the 30-30. a 308 factory load excededs the presure limmit that these old guns where designed for by a hefty margin. I assume that the new 7.62 barrels are of a much better grade of steel than the poor grade steel that the actions are made off.