ORIGINAL: quiksilver
I don't really have any hard evidence on which to base this fantastic claim, but I'd venture to guess that the 30-30 Win. has killed more deer than just about any other cartridge.
There's absolutely nothing wrong wth 30-30 as a deer hunting gun. There are many a hunter who harvested his first deer with a Marlin or 1894 in that chamber.
I would bet that the 30-30 has killed more deer than any other cartridge, also. I have one with iron sights I used to take my first deer. The deer was dead before it ever hit the ground.