I would say on the longer bullets back off to .06 off of the lands and see how that does. Then work to closer if needed. I tried that long loading to .02 off the lands in my bolt action, groups were opening up greatly to .75 to 1.5 MOA. At .06 off the lands with bullets from 69 to 77 grains were giving great results of under .25 MOA. With the 55 grain bullets I tried different lengths and the results were so close I just seat them to mag length.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.