I found Culpepers. Thank you.
I tried a new load today to see if perhaps the powder/brass was a problem as headspace is not excessive.
I loaded up IMR-7383 under a 200 grain bullet. I lightly lubed the brass to allow the brass to form to the chamber walls. The fired case is identical to a new virgin case other than the shoulder angle. No case stretching.
I'm beginning to think the brass is at fault.
I reloaded the same case five times ( neck sizing only) with no splits.
This powder is slower burning than IMR-4350 and IMR-4895. This may be the powder to use to save the brass.
I will try the load tomorrow at 385 meters and see how it holds up and how accurate it may be. They are calling for winds up to 40 mph.