The 7.62x39 bolt will not work in th 5.45 carrier.. I am also not sure the 7.62x39 bolt will work in the 5.45 trunnuin either... ?You might be better off to build another gun..lhead said:Can anybody tell me if exist a 7,62x39 bolt that I can fit in my 5,45 krink bolt carrier? I?m planning to change the caliber...