I think that the intent was to achieve a smoother fit in saddle scabbards, particularly for the full stocked stutzen carbines.

They look nice but are not as handy to work with as a conventional bolt, particularly for a left hander like myself.

On Mannlicher Schoenauers there is a locking spring just behind the bolt handle. It is important to ensure the bolt is pushed all the way down into battery over this spring as otherwise a misfire can result.