When I was in my formative years I was addicted to gun magazines, which were a hell of a lot better then than they are now. One of the staples of these publications was the piece on killing power, or knockdown power, or whatever you wanted to call it, in which a writer who had been everywhere and shot everything (or had been almost nowhere and shot almost nothing) would prove beyond the shadow of a doubt that if you used his cartridge of choice, every time you pulled the trigger something would stand on its nose and then collapse in a heap.
I’m thinking about this stuff now because I’m going back to northernmost Maine where the deer are very big, the cover is very dense, and following a blood trail is very difficult. In addition, I’ll be watching a clearcut where I can get a shot at 300 yards, so what I want is a rifle that will shoot nice and flat and knock the buck flat or, if that’s not to be, put a big hole through and through so I can get a good blood trail to follow.
I’m sorely tempted to take a .338 loaded with 210-grain Barnes TSX copper bullets, which shoot very flat and will go through nearly anything. Or I can take a 6.5/284 loaded with 140-grain Nosler Partitions which shoot very flat and will go through nearly anything.
Killing power doctrine notwithstanding, there is no difference between the two, except that the .338 kicks more. Having killed who knows how many deer, both mule and whitetail, over the course of 40-plus years, with everything from a .223 to a .340 Weatherby, I can see no difference in effectiveness from one cartridge to another. Shoot them fatally and they will either drop on the spot or drop within 100 yards. Shoot them other than fatally and it doesn’t matter what cartridge you’re using; you’ve got a mess on your hands.
So, because I don’t like getting kicked as much as I used to, I will probably take the 6.5/284. Or a .270. There’s no difference.