I purchased a 7.62 Nato Israeli Mauser. In the interest of safety I took it and had it headspaced. The extractor was removed and bolt partially disassembled before the test. The smith used a .308 field reject for the test. The bolt started a turning motion but did not completely close. He told me the rifle was probably not safe to fire. The field reject gage was 1.638". After doing a little research I have found that 7.62 Nato has a 1.640" no-go and a 1.645" field reject. Based on the bolt not completely closing on 1.638" it is entirely possible that the rifle is within the Nato no-go specs and well within the Nato field reject. Based on that I think the rifle should be okay with Nato ammo but not commercial .308 ammunition. Am I wrong? Any opinions, advice or help would be welcomed.