I've worked on a lot of wbys. You can open the standard mag bolt face (257,270,7mm300 and 340) up to the big 378 wby, lapua or Norma bolt face very easily. You will need to change the extractor out as they are different. Also if you plan on going to the bigger wby (378 class) you will need to mill the bolt stop slot in the bolt longer and put the longer mag box in, also very simple. Gotta love weatherbys
