No slug is a long range tack driver. One gains a bit with the better sabots, but shots over 125 yards are too chancy for me. Some of the new slugs duplicate the ballistics of a hot 45-70, say 400 gr at 1600 FPS. The venerable 45-70 is not thought of as a long range cartridge and hasn't been since around 1880.
If somone needs a 200 yard deer gun, they should buy an '06.
Or learn to get closer.....