I would say perhaps they learned from the SA Target Actions, with the added mass from the small ejection ports and the re-located action screw locations that supposedly helped make things stouter and resist failure all around... even the 111LRH has a small ejection port action now.
As far as I know, no major changes to the exterior dimensions of the bolt or the receiver... just some extra metal in places. The rim of the bolt still looks *awfully* thin when you look at it...
Bookmarks