The Fat Wrench comes in handy for a lot of different torquing jobs,(scope rings/action screws) so you can't go wrong buying one of those. The lapping can increase the contact area between the scope and the rings once you put them together. I won't say its not worth going the extra mile, but in most cases its not necessary. My response almost two years ago:
« Reply #7 on: February 21, 2018, 10:17:19 AM »
I put my Buckmaster 3x9x40 with Talley low mounts on my Vanguard without any problems.( no lapping) A good hardy hand tight to finish. Put front and rear rings at the same time and and when you feel the screws start to snug up stop. Do the same to all. I used the diagonal method and tightened each screw a little at a time, and what you want is to try to keep the same gap or space between the rings on both ends. Easy peasy. I did leave the laser bore sighting to a gunsmith.
Midway USA has a library of videos and I'm sure they offer some help on bore sighting if you want to try and save money. Heres an old "how to" video on lapping by Wheeler. If you're interested.
https://www.youtube.com/watch?v=L4oF_07X1qU