Like was said above, a hex wrench is measured flat to flat. You are trying to use it point to point. A .050 wrench measures about .055 point to point and a .0625 about .069…so no, it won’t fit in a .0625 hole.
You can get a Howa mini barreled action from Brownells for $415 and put it in a chassis/stock of your choice. Not as smooth as a Tikka, but they’re good shooters.