I shoot heavier bullets in my 270 WIN, which is an older Remington 700 BDL...as it seems to prefer the 150's, so that is what I stuck with.
My best load to date (1" groups @ 100) has been 150g Nosler Ballistic Tips, pushed with 50g of H4350, Federal Premium GM210M (Match) primers...but I have had good luck with IMR 4895 as well.
You may want to try a different bullet brand/weight or try more powder combos. Not sure why you would want to duplicate the factory load, as you state that that load only shoots god, not great through your rifle. Anyway, my experience has been that it may take several different combos tried before you find the right one. I have some rifles that prefer one brand of brass over another and some that are picky about the primers...and some that shoot anything you shove down it well...happy reloading and good luck!