Something isn’t right. I’m not sure what 185 your using but with my math (could be wrong, I’m half asleep) your only getting .044 of bullet (not counting the boat tail) into the case neck when loaded to the lands. That’s with a 185 hybrid.
360 thou is a ton of jump. Can’t say I have ever tried to get anything to jump that far. I would contact whoever chambered it and see what they did. They may be able to set it back and get you closer to where you need to be. I’m not real familiar with the wsm but that throat almost has to be for something like a 230 hybrid in a long action.
You didn’t say what action you have but with the WSM’s I have played with if your going to be loading Bergers it certainly helps to have a extended magazine box. If that’s not an option then maybe look at the Berger classic hunters. They fit better in the WSM’s if you have magazine restrictions.
Best of luck. I would take this up with the builder.