I've read plenty of people arguing about whether "light and fast" or "slow and heavy" bullets are better for self defense. I've also seen a number of people say they would reach for an AR-15 platform or something in that ballpark before reaching for a glock to defend their homes. I don't personally buy into the whole "your an idiot if your not using a 45" thing, but considering there has been some controversy over the 9mm being too light and or too fast to have adequate "stopping power", how can an AR-15 platform in 223/5.56 be better. I realize AR's have a tremendous range advantage, and typically a magazine capacity advantage, but a 55 grain FMJ bullet doesn't sound ideal to me in a home defense environment, even though it has much higher velocity. I would expect over penetration to be an issue at close range too. How would you compare say, 9mm or other pistol calibre hollowpoints to an AR type rifle?