If you have access to headspace gauges there is no reason you have to ship the
action. I would however do it so the gunsmith can check his work and there is no
question about who did what. Also you will find there are two reamers out there. The
original 8mm mag case sized reamer, which should clean up the old chamber without
setting back the barrel, and the "new" (chasing the factory's smaller brass based off
the 300H&H case ) smaller diameter brass which seems to be the standard now. I have
read posts that the smaller reamer does need the barrel set back to clean the 7mm
chamber.