This all depends on the shooter, as has already been said a few times...
A skilled, well practiced, shooter with a 30-30 can accurately shoot farther than a novice with a 7mm Rem Mag.
Give that 7mm Rem Mag to the skilled and practiced shooter...and he can put deer down clean at 800 yards...much past that, the bullet slows down so much that it no longer expands properly...most require about 1,800 fps to reliably expand.
Give him the 30-06...and its 600 yards.
243...it gets pretty weak past 300 yards, can be accurate much farther, but that little bullet can't do much damage once it slows down.
If you're asking about point blank range...as in, point and shoot, no holdover or scope adjustments...then for the 7mm, 243, and 30-06...its 250 yards for all, given proper barrel lengths and muzzle velocities...if they're sighted in for 200 yards.
Sight them in for 250 yards (this is what I use)...and they'll reach to 300 with 3-5 inches of drop, below the point of aim.