if you are not getting good groups with the bullet seated fairly close to the lands, to try seating them deeper.
I agree whole heartly with them. It worked out great in a 300RUM I had. I was shooting A-Frames, and getting 2MOA groups, I moved it back and back and back from 3.62" COL to 3.55" and got it down to subMOA.
Alot of poeple Roskoe has this conception that this changes harmonics and all that, but you have also changing the load effectively. And will be increasing pressure for most powders the deeper you go.