Hornady makes a brass headspace comparator kit that works well. Measure the brass that chambers easily against brass that does not. Then it's just a matter of die adjustment.
If you are already getting heavy cam-over with your press and still need to bump the shoulder more, you can get...
22-250 shoulder is 1.515, 22cm shoulder is 1.49.
While the difference is only .025, it's better to set back .06 or so (1 turn on a tikka), so you can true up any runout in the factory chamber.
Not as simple as just running a reamer in there.