Yeah I guess so. I don't have the case dimentions but the photos look as if the diameter at the shoulder of the 400 may be a bit bigger than the 9.3.
The deal is that I would like to build a back up rifle for use on scrub bulls that can meet the following....
Be built on a standard length action....
Not need to have bolt face or extractor opened up....
Use easy to get brass....
Shoot a 400gn Woodleigh at a min of 2000 fps....
Weigh no more than 8 to 8 1/2 pounds with open sights....

Had plans to do it on a Brno ZG or a pre 64 Win but both rifles I was looking at were sold while I was away!