Daryl,

The 400 Whelen in its original or standard form was on an improved case. The only versions that used a non-improved standard 30-06 case were done by gunsmiths who did not understand what Colonel Whelen had designed in the 400. Michael Petrov's excellent articles on the 400 Whelen are easily found online and a worth while read and do a great job of explaining the 400 Whelen's history.

The 30-06, 35 Whelen and 375 Whelen all share a common .441 shoulder diameter. The 400 Whelen as The Colonel designed it has a .458 diameter shoulder. There are other variants with a .461 shoulder and of course the Brown-Whelen with the shoulder moved slightly forward and a .461 shoulder. I'm not sure what the dimensions on the 411 Hawk are but all three cases, the 400 Whelen, the 400 Brown-Whelen and the 411 Hawk are so close in capacity that load data is interchangeable.

My 400 is the standard 400 Whelen with the .458 shoulder.

Mart