As a note when most people say 7.62 it is generally short hand for saying 7.62 NATO. They usually specify if it is one of the other 7.62 rounds. As well the .308 is a similarly cartridge round and 7.62 NATO rounds can be shot from a .308 gun but 7.62 NATO guns should not be used to shoot .308 rounds as the .308 has a slightly higher chamber pressure.