Jeff, are you and Shawn using a 35 degree shoulder with body taper more similar to something like Kirby's 338 Allen Express or more of a "Ackley" style with a 40 degree shoulder and body taper?? I know there are a lot of different 338 Lapua "improved" versions out there but they all seem to yield nearly the same case capacity. Usually around 124-125 water grains.
Are you going to test different powders or are you pretty set on VV570? I'm not sure if Shawn every got around to testing any but I know he had some of the new RL33. It looks to produce some pretty good FPS numbers but I have no clue how temp stable it is or what kind of ES #'s it produces. US869 is a bit on the dirty side but it always seems to have some of, if not, the best FPS.
Also, I'm curious to hear how much case length you lose when you improve yours. If I remember correctly I lose about 40thou. of overall length when the shoulders are blown out.
As close as you and Shawn are getting to having your LRKM finished, I bet you can hardly sleep at night.
I look forward to reading about your new best friend.