Norco, if it's 1/4" clicks, then each one will move the point of impact 1/4" at 100 yds.
Not knowing the exact ballistics for the 270 WSM, I'd say if you are 3" high at 100 yds. it would put your zero well past 200 yds.
I don't know what you have been reading, but it may have been about a 3" maximum point blank range, which is different for each caliber and bullet weight. Meaning that sighting in at a certain point above zero at 100 yards, your shots will not be higher or lower than 3", at any range out to some distance between 300 and 350 yards, (so you would be able to aim "dead-on" and not have to hold over/under at any distance inbetween.) This maximum distance will also be different for each caliber and bullet weight.
I prefer to sight in at a known range of 100 or 200 yards, compared to using a maximum point blank range. Good luck!
Frank