600 meters? That would be tough. You’d only get about two shots before they start to return fire.
Granted the sights say a thousand meters(I think, it might be 2000), but that’s meant to be done in large volleys shooting at very large targets or massed troops.
In other words, it never happens.
There are many people on record that have hit out to 800-1000 meters with a Mauser 98 in 8mm Mauser using only the iron sights.
And there are any number of dead US troops from WW2 that were casualties of the M98.
Also, it takes them a while to figure out where the rounds are coming from, if the shooter does his job properly.
Finally, I’ve seen someone get off all five rounds and get 5 hits on 5 separate targets at 800 meters in about 10-15 seconds. So it’s more than possible.