According to Ruger, the cyl gap should be between .003 and .009". My 44mag has about .004". I haven't checked the 454 since Ruger fixed it but new it was less than .001 on one side and .006" on the opposite side. Crane was screwed up.
My other barrel for the 44mag has about .006". It started life as a 9 1/2" and has morphed into a 6 1/2" . It's next life might be 4 5/8", I haven't decided yet.