Rex,
Generally I start a little farther off the lands than with lead-cored bullets, around .050 inch instead of .030 or so. If that doesn't work like I want it to, then I start seating deeper, usually around .03 for each trial. Have often gotten better accuracy at around .1 inch off the lands, but in some rifles it's been much more.
One I remember specifically was a Mark V Weatherby in .270 Weatherby Magnum. I started handloading for it with 130-grain Ballistic Tips, because they have an ogive very similar to E-Tips. Got fine accuracy (as I recall around 1/2" for 3 shots) with the bullets seated as far out as possible to fit in the magazine, which in a Weatherby is already quite a ways from the rifling due to the long "freebore" chamber throat.
Then I switched to 130 E-Tips, with the same powder and seating depth, but they grouped into about 2". So I started seating them deeper, two turns on the seating-die screw each time. The first groups (2 turns) were around an inch, and the second groups (another 2 turns, 4 in total) were around what the Ballistic Tips had done, a little over 1/2".
