Historically forming the 338-06 is an easy process, just run a 30-06 Govt case into a tapered expander 338-06 sizing die, load, and shoot. What most articles/reloaders don't tell you is that the cases come up a few thousandths short. I've heard that using a 270 Win or better yet a 35 Whelen case will give you resized cases of the correct length after minor trimming.
For those who are shooting the 338-06 (A-Square per SAAMI) what are you using to form cases. Of course, the simple answer is to avoid the whole process and just buy 338-06 factory cases...except for the component shortage and the fact that the 338-06 is only moderately popular makes that hard to do.
Any experience offered will be appreciated,
Thanks,
Paul