Going on the premiss that there are no dumb questions, just dumb answers , I'd like to know ifthe G5A.S.D. will work on an arrow with the inserts already installed or does it work on shafts prior to installing the insert? And, are there any "special" hints to using one? Thanks in advance for any replies.

Squaring the insert is better than nothing, but if you square the arrow then the insert, you'll have it all but perfect. Using a black marker, color the end of the insert and shave it off until all the black is gone, you will then know the insert is square.

Thanks mobowhuntr. Since my inserts were alreay installed this is good to know. I've also heard that's a good idea to square-up the nock end as well, is this good practice (I'd do this when re-fletching of course)?
Thanks again.

The straighter and more square everything is, the better. Squaring the nock end as well would do nothing but help....

I have one and it works wonders. I always start with the nock end and then square the insert end before installing the insert, and finaly the insert it self. Just for the heck of it I screwed on a broadhead the other day on an arrow that everything had been sqaured except for the insert itself and spun it. I wasnt too happy, I had quit a bit of wobble when I spun it. I unscrewed the broadhead and squared the insert, wala no more wobble. I was once again a happy camper.