If you are FL sizing Prolly 5 or 6. You will need to trim around 3rd firing. If you want to go over 6 you will need to trim again.
I am assuming max loads....why else have a WSM?
You might get case neck splitting but my experience has been primer pocket.
It is somewhat disconcerting to prime a piece of brass and have the primer fall into your lap.
You will know, the primer pocket and primer will be discolored.