My general experience with the 9.3x62 is the added bullet weight and diameter does result in quicker kills, on average, than the .30-06 with heavier bullets. In fact haven't been able to tell any difference between the 9.3x62 and .375 H&H.
But have also noticed less difference in "killing power" with widely varying big game cartridges the longer I hunt. Suspect it would take more than one typical "plains game" safari to see any difference between 200-220 grain bullets from the .30-06 and 250-286s in the 9.3x62--or the .375 H&H.
