I hope you don't mind me sticking my two cents in here. "Dead Nuts" is an old rifle factory term. When the bore machines were set up perfectly, they would apply locking nuts (called "dead nuts" or "dead sets") to keep it that way. So, when a rifle barrel was made on such a machine, it was made "to dead nuts". It became a reference to the quality of build and accuracy of the rifle.
Good info Rosco. Heard that term for years, never knew where it came from.