It happened again at an afternoon barbecue a few months ago. A new acquaintance commented he was looking at buying a new pistol.

"What caliber?" asked the other new acquaintance.

"I don't know," first guy said. "Nine millimeter, I think."

"Huh," sneered the second new acquaintance. "Just going to tick him off."

The first new guy shrugged helplessly as if to say, "Well, what do I know? I bow to your superior experience and ballistic knowledge."

I generally try to not comment when people make stupid statements about guns. It's like arguing with a drunk or a dog. When it's over, the guy will still be drunk, and the dog will be confused.

But this fallacy has become so entrenched in our gun culture, I can't keep quiet - at least once monthly someone makes a disparaging remark about the effectiveness of the 9MM cartridge in handguns.

I try really hard not to sound as smart-ass as the second guy when I comment - sometimes, I'm successful.

"Let's see," I chimed in at that moment. "That shooting that occurred up there in Blacksburg, Virginia in 2007 at Virginia Tech. That South Korean nutcase, Seung-Hui Cho - he killed 33 people with - oh yeah - a nine millimeter.

"And the Luby's Cafeteria shootings in Killeen, Texas, back in 1991. That guy killed 24 people with a - oh yeah, a nine millimeter. But a nine millimeter won't kill anybody. ..."

The current disaffection in this country with the 9MM pistol cartridge can be traced back to the infamous Miami shootout in 1986 between two heavily armed armored trucks and bank robbers and the contingent of FBI agents that had been hunting them.

Armed with an arsenal of weapons including a Ruger .223 semi-auto rifle, these two killers had decided they would not be taken alive.

The resulting shootout left two agents dead, several more severely wounded, and both perpetrators dead from multiple gunshot wounds.

Probably no gunfight, with the exception of the OK Corral, has been more thoroughly dissected and reviewed, and its aftermath resulted in a sea change in the manufacture of handgun ammunition.

The FBI centered on the 9MM Winchester/Western Silvertip Hollowpoint fired at Michael Platt by agent Jerry Dove (who was killed in the incident).

Dove's shot was exceptional, putting the round through Platt's right arm and into his chest cavity, where it stopped 1 inch from his heart. Had the round more power, according to the research from the FBI, Platt's heart would have been penetrated, and his ability to carry on the gunfight (he took 12 rounds in all) would have been about 30 seconds, instead of several more minutes during which he killed two agents and wounded five more.

We're not going to get into another dissection of this gunfight - go to your search engine and type in "FBI Miami Shootout;" there's even a YouTube cut of the made-for-TV movie "In the Line of Duty: The FBI Murders" with a Hollywoodized version of the shootout.

The FBI later hosted the famous "Wound Ballistics Seminar" which resulted in the adoption by that agency of the 10MM semi-auto round - basically a .41 Magnum in semi-auto form - and the S&W Model 1076 pistol.

From this round came the descendant .40 S&W, which became the rage in the mid-1990s of police departments across the U.S.

The book that answered all questions and (to most ways of thinking) settled all arguments was the 1992 "Handgun Stopping Power" by Evan Marshall and Ed Sanow.

The original book studied shootings from a position never seriously reviewed before: actual documented street shootings.

The authors reviewed thousands of shooting incidents, mainly by police officers across the country, with some very exacting standards - only "one-shot stops" would be considered.

Their definition of one-shot stops had several restrictions - but the basic stipulations were the perpetrator could be hit only once in the torso, and if he moved, he could not move more than 10 feet before he collapsed, unable to continue the attack. Multiple shots were not considered. From this mass of data, the authors worked up percentage tables of one-shot stops on every common form of handgun ammunition. The results for 9MM were fascinating:

At the bottom of the list of 17 different rounds was the W-W 115-grain FMJ (Full Metal Jacket). With 148 shootings reviewed, it had an average muzzle velocity of 1,149 FPS, and 90 one-shot stops for a percentage of 60.81.

At the top of the list was the Federal 115-grain JHP (Jacketed Hollow Point) +P+. With 56 total shootings, and an average muzzle velocity of 1,304 FPS, it had 50 one-shot stops and a percentage of 89.28.

The second most effective round was the W-W 115 JHP +P+ with an average muzzle velocity of 1,299 FPS, 51 shootings, 45 one-shot stops and a percentage factor of 89.28.

The FBI Miami Shootout and the resulting Wound Ballistic Seminar resulted in vast amounts of research being poured into handgun stopping power, and the effectiveness of such has been immeasurably improved because of these incidents and actions.

But the fact remains that a handgun is a tool best used to hold them off until you can get to a rifle or shotgun - NO handgun round will have the devastating tissue damage and resulting incapacitation of a centerfire rifle or shotgun.

That being said, the 9MM remains the choice of handgun caliber across the world for many law enforcement and military organizations. Of course, any more powerful, faster, heavier cartridge - the choices are endless - may have a better chance of stopping an attacker, but as most experts will tell you, bullet placement has a heck of a lot more to do with effectiveness than choice of caliber or bullet.

I personally like 9MM and own several different semiautomatics in that caliber. I carry them concealed all the time. I like the fact that smaller pistols with large capacities have been designed around the caliber, and I like the fact the ammunition is available practically everywhere, and comparably cheap practice ammo allows me to shoot regularly without taking out a bank loan.

Remember - the best gun to have in a gunfight is the gun you bring to the gunfight. If you feel comfortable with a particular design of 9MM, don't let the naysayers dissuade you. I'd rather shoot someone with a 12-gauge shotgun loaded with 00 pellets, if I want to absolutely do the most damage and stop them the fastest.

Unfortunately, it's a little hard to strap a 12-gauge on my hip and cover it with a shirt or jacket. In turn, I'll carry my compact 9MM with 13 rounds of +P+ hollowpoints - and strike out into the unknown feeling only a little less protected.