I have a 110 (stagger feed) that was a 243. I turned/threaded a 300 WSM barrel to fit and installed the barrel and mag bolt face.
I need help on how to get it to feed. The original 243 mag would not allow the fatter WSM case into the mag box. I opened both sides of the box. The first one fed fine when I pulled the bolt back to extract-eject, the next 2 rounds would pop out of the mag box. I bought a WSM mag box and I am having the same problem - the feed lips are too narrow to get a WSM case into the mag box. On top of that, now the boltface hits the WSM magbox lips and will not allow the bolt to close.

I need advice as I would like to get this up and running.