My best guess would be the .30-06 has killed more deer at this point. As best I recall, the .30-30 was #1 in ammo sales up until about 1960 when the .30-06 finally overtook it. The .30-06 then remained in the top position until about 10 years ago when the .308 displaced it as #1 in the "big game hunting" cartridge category. {the .223 beats them all in CF rifle ammo sales but most of that is probably shot at targets and varmints}. Since there were more deer and more generous bag limits after 1960 than before it is probably more likely that the .30-06 has killed more deer than the .30-30.
