The Carcano M91/38 is a magazine fed rifle, it isn't manually reloaded. You can work the bolt while remaining on target. That's not a particularly hard thing to do, either- I was able to learn that skill the first afternoon I shot a magzine fed bolt action.
EDIT: Here's a video of someone replicating the shots with that rifle. https://www.youtube.com/watch?v=ghmY6HmR4fs The comments also point out other factors that could have made the shot easier.
