+1 for the Barnes TMZ bullets. They are extremely tough and expand exactly the same whether you shoot them through tissue or bone. I spine shot a bull at 89 yards several years ago with a 250 gr. TMZ and 2 777 Magnums, and he dumped in his tracks. The bullet went through the thickest portion of the bull's vertebrae, and lodged under the skin on the opposite side. After having passed through two inches of bone, it was still perfectly expanded and had retained all of its weight with the exception of the plastic tip.
There was an Outdoor Life test a few years ago that included the Shockwave, and they found that it was fragmenting badly and not retaining weight very well (about 75% weight retention, if I remember correctly), so I won't use Shockwaves. I know some people like Shockwaves, but having a bullet that retains its weight and does not fragment is what you need for elk and what you'll get from the Barnes. They are excellent bullets, and it is the only bullet I will shoot in my muzzleloader (until someone makes something better).