I worked up in .5 gr increments on mine. Started at 87 gr and stopped at 91 gr H1000. No pressure signs but stopped because of the small groups and 6fps ES. Also this is shooting the 215 Berger Hybrid, Stock Sendero.
I recently tried it with my 270 out of curiosity, except instead of droping the charge 2gr I dropped it 2% due to the smaller case capacity, then tried 2 different primers, and got grouping better than I've ever seen out of it, certainly better than I expected to see. Switched the 243 to 95gr Bergers and I'm trying Kirby's method again, we'll see if it works again.
For most rifles I go in 2% charge weight steps. That would equate to 2 grain steps for the 30 rum. It seems rather foolish to me crawling up to pressure with a 1000-1500 round barrel life gun. If I find one charge is close and the next one up is warm I'll linger a bit between charges, but for the most part 2% has worked fine for years.