Would not even consider fitting a scope without lapping the rings.
For leupold type rings, the first step is to make sure that the ring is at 90 degrees to the bore; use a 1 inch tube ~3 foot long lock it into the front ring and rotate the ring until true with the end of the barrel and bore.
Then align the back ring using pointed 1 inch bar stock, 1 piece for each ring, adjust the back ring as best as is possible so that ideally the 2 points align perfectly, never happened yet!
Lap the rings, I use bar stock and valve grinding media, have never used the reamer type lapping tool, it may be better; the front ring will be better lined up than the rear, concentrate on keeping everything true.
Clean the rings well, then bed the scope into the rings with Devcon, make sure not to forget the release agent on the scope..
It is a bit of effort to do correctly, but the results are worth while.
Scope is properly aligned, held securely with a minimum of screw tightening and there no ring marks.
Only draw back is that not all 1 inch scope tubes are the same diameter!