Hi.  Welcome to the forum.

As far as I know, cracks are usually evident with the named eye.  Back when the problem arose as a result of the Army trying a different hotter round in 1898, there was no magnaflux inspection.  The cracks were discovered visually.  As long as you stick to established pressures and stay away from max loads, you should never have a problem.  If you're concerned however, have your bolts checked by a competent gunsmith... one who KNOWS about Krags!  How about sharing some pictures of your Krags?