From the Sierra Website:
"Within their caliber and for their weight our toughest varmint and hunting rifle bullets are hollow points. By "toughest" we mean that Sierra hollow point GameKing rifle bullets expand less and penetrate more than their lead and plastic tip counterparts, the Spitzers. That is the opposite of pistol bullets. It is also the opposite of what everyone except those who use them would think of our hollow point GameKing rifle bullets. Still, it is true of each Sierra hollow point from the little .224 40 grain HP through the 165 grain 30 caliber HPBT.
While our flat base hollow points are tough varmint bullets that can put down coyotes, our hollow point boat tails (except for the 55 gr. .224 bullet) are excellent medium and big game bullets capable of antelope, deer, black bear, moose, and elk. These hollow points were designed with hard cores and heavy jackets to not only eliminate tip deformation, but also to withstand the higher impact velocities often incurred at the closer ranges. As with books, bullets cannot be judged from its title or a look at the outside. The next time you are in the market for a bullet that will penetrate better than a similar weight Spitzer or plastic tip look for a Sierra hollow point hunting bullet. Their accuracy is often only second to our MatchKing target bullets, the world's standard. As always, we welcome your comments and questions concerning the specific use of our bullets. We never tire of your stories and photos. Often we feel like we were there with you. In a way we were."