I bought a MAS 1936 at a gun show in Jackson, MS yesterday. It has been converted to .308. I stopped at a gun shop on the way home and had the headspace checked. It closed tight on a .308 no-go gage. I have heard that if it closes tight on a .308 no-go that it is safe to use 7.62x51 surplus ammo. Is this true or not? I am going to take it to another gunsmith for a complete checkup.