I disagree with the suggestion above that an unnecessary repeat resizing will do no harm. It's likely that it would shorten the number of reloadings before his brass separates at the head.

The bolts of most bolt actions are easily disassembled. I'd remove the firing pin to better feel whats going on then try to close the bolt on a case. Contact between the chamber and case shoulders is ideal. That extends brass life and can improve accuracy.

Gauges are for making cases so small that they'll be sure to chamber in every simi-auto that has a chamber within specs. That's typically not the goal of a reloader loading for one bolt action rifle.