[Jeff Higgins]

Good call, sniper. Penetration is vitally important in handgun ammunition, along with a bullet shape that will cut its way through tissue, as opposed to pushing its way through.

Handguns, even the most powerful, are woefully underpowered when compared to rifles. We have to make choices. Rifles have the power to both penetrate deeply and expand the bullet, where handguns do not. It's one or the other. Forced to make a choice, the only one that makes sense (especially in big game hunting) is penetration. Fortunately, big bore handgun bullets are already about as big in diameter as a typically mushroomed .270, 7mm, or .30 caliber rifle bullet. If we can extract equal or better penetration from them, we can equal the killing power of the medium bore rifle.

Self defense with small caliber, concealable handguns is governed by the same set of rules. Yes, with a large bore handgun we can get full penetration and good expansion on human targets. Not so with the small caliber sidearm. Expansion does us no good in these, as they are already somewhat challenged with regards to penetration. Expanding bullets in the .32's and .380's have been known to have been defeated by heavy raincoats and other winter clothing. If it never even makes it into the boiler room, it matters little how nicely it mushroomed.