Use your mike for setting up the dial bore gauge zero, make sure and use the checking standard for your mike to ensure that zero is zero on the mike
I have a Sunnen dial bore gauge that rears in .0005 increments, not the better .0001. , I also got the checking fixture for it but I don't use it do to the possibility of errors by stacking the checking standards and dirt or dust getting in between those parts, I don't use it now.
I also have a Mit (SP) dial bore gauge that does read in .0001 increments so I use it instead of the Sunnen