Most all precision rifle shooters know exactly where their "cold bore" shot is going to go.
If they knew is was going to be a 600 yard shot, then it would end up being similar to just a 1 shot F-Class match at 600 yards....not exciting at all.
However, if you made it unknown distance, with 60 seconds to take the shot and not allow laser rangefinding devices.... That could be more interesting. Not only would you have to make 1 shot count, you would have time pressure of ranging the target and then firing the shot.
And differentiating by caliber is not necessary; not only is it not necessary, it shouldn't be done.
Weapon must not have been fired prior to match, cold bore ambient temp only.
I think I know what you mean here.... but taking it literally means that you are asking competitors to buy a rifle off the shelf and then try to shoot it at 600 yards without ever