Give me a call when you get a chance and I'll fill you in on the twist in the new barrel.
I have some of those solids from Dave but I'm a little reluctant to put them through the barrel due to their material.
Cases of both my .338 and .375 are nearly identical to yours.
Here's the picture of my .338-408 aka.. Big Baer that Paul from 6mm BR used when he wrote the article about the 3.806" group I shot at 1,680 in the early spring. It's next to a 6x47 Lapua and that's the 300 SMK in the neck.