Provided you know some very specific things about your setup (arrow trajectory being one of them) you can in fact sight in close and be reasonably close at longer yardages. I have used this method in the past (and a good working knowledge of TAP) to calculate the 8 yard point of impact when using my 20- 60 yard pins.

Unless you are very techically savy I would not recomend this as anything more than a roughing in of your pins. Shoot the actual yardages to get them right.