Just load a few at different lengths and try them out, my 300 win mag likes to be just off the lands (RL22)and my .338 needs to be backed off for best accuracy (RL19). try loading 5 of each distance and see what the best results are and go from there. Don'tseat the bullet touching the lands as this can create a dangerous build up in pressure, unless you are fire forming cases with reduced loads.

ws