The Mannlicher-Carcano was strictly for field personnel, it was never intended as a sniper’s rifle.
Of course, it didn't need to be a long-range 'sniper' rifle considering that the shots fired at President Kennedy by Oswald only ranged from 44 to 88 yards. Any military rifle of the 20th Century will hold a 4 inch group at that range, and the grouping on Kennedy was about nine inches for two shots with one visible miss.
Entirely expected results, really.