The oxide film that hot blue makes is so thin that it is difficult to measure even in a top notch metrology lab. I have never heard of it affecting accuracy in 50 yrs in the gunsmithing hobby.
Benchrest shooters are no different than many other segments of the shooting hobby in that they are ready to believe almost anything suggested by so-called experts even if it might violate physical laws. They are especially susceptible to anything that might excuse worse than average groups. In other words, forgetaboutit.
RAN
