Anytime firearms are discussed, especially when it comes to defensive use of weapons, the caliber debate is going to come up. This is one of those debates that will probably never end, just like the "Modified Weaver" vs. "Isosceles" rap; there will always be a differing of opinions. But, when it comes to discussing calibers we need to do it based on actual data, and not myths or outdated information. A lot of people don't realized it, but hollow points and ammunition specifically designed for stopping threats are fairly new, especially when you consider how long people have been shooting other people. For example, you'll hear people talk about how ineffective the .38 special round is. And at one point in time this was true, but what most people don't know is that when this caliber was widely used by law enforcement officers the standard round was a full metal jacketed bullet. This type round doesn't expand, fragment or dissipate its energy very well. The bullet usually retains most of its shape, and punches through tissue unless redirected by serious bone structure. This was a concern for shooters, and people often experimented with different ways to increase the bullet's effectiveness. Chic Gaylord – who documented and studied a lot of shootings - mentions in his book, "Handgunner's Guide," that "jacketed bullets are not so effective as lead bullets of the same weight," and adds that bullets "having a flat nose, as in the 'wad-cutter,' are more destructive than those with pointed noses." Jim Cirillo also covers bullets and stopping power in "Guns, Bullets, and Gunfights." Cirillo had a lot of experience shooting people, and experimented in bullet design to increase stopping power. Ultimately he came to determine four factors that affect stopping power: Bullet construction and configuration, bullet diameter, velocity, and bullet weight. The information and data was out there, but it was a long time before people really started paying attention. For example LAPD didn't issue hollow point bullets to their officers until 1990. The New York City police department switched from full metal jacket bullets to hollow points in 1998. Taking this into consideration there are a lot of bullet stories out there based on full metal jacket rounds, and good calibers, like the .38 Special and 9mm, got a bad reputation for "not being enough gun." In the past few years the design and development of bullets has come a long way. Remember Cirillo's list above. Number one is the round's design and construction. Modern technology has covered this pretty well, and it's still ongoing. Bullet diameter is a consideration, but take a look at An Alternate Look at Handgun Stopping Power, by Greg Ellifritz. His study reveals that the average number of rounds fired until the threat was incapacitated doesn't vary a lot between the .380 caliber – with an average of 1.76 rounds fired – the 9mm, with an average of 2.45 rounds fired, the .40 S&W – 2.36 rounds - and the .45 acp, with an average of 2.08 rounds fired to incapacitate the threat. (An interesting fact in his study is that with the .22 there was an average of 1.38 rounds fired to stop the threat.) Keep in mind most stops are "psychological," the threat could still continue, but decides not to. One-shot stops, or shots that totally eliminate the threat's ability to fight are rare, regardless of caliber. Ultimately you need to determine what you can shoot accurately and efficiently, what you will carry – a large frame, big caliber in the safe at home won't do you much good – and then train and practice until you gain confidence in your skills. Use a well-designed "defensive" round that will function in your weapon. If it's necessary to shoot, concentrate on good accurate hits, and repeat as necessary. Tiger McKee is director of Shootrite Firearms Academy, located in northern Alabama. He is the author of "The Book of Two Guns," writes for several firearms/tactical publications, and is featured on GunTalk's DVD, "Fighting With The 1911 - http://shootrite.org/dvd/dvd.html Website: www.shootrite.org http://www.facebook.com/pages/Shootrite-Firearms-Academy/156608611038230?ref=ts