Re the R93/ I know the Australian Federal Police tested the holding power of the bolt by breaking of one locking petal at a time until down to just 3. These were spaced equal distances apart. Calibre was either 300WM or 338 Lap, do not know which one. It held.

However if it didn't lock up properly look what happened. Yes all of them have very fine tolerances and as I understand it high maintinance to keep them reliable in very dusty conditions.