9mm vs .45ACP: Really? Again?

Yes, again. Amongst avid handgun fans the debate between big and slow versus small and fast stretches back over a hundred years now I'd guess. Next year marks the 100 year anniversary of the Government Model 1911 .45ACP having been adopted by the U.S. Military (even though it existed in 1904) and the 9mm is even older than that. What makes the debate relatively new (and hopefully interesting) is the addition of what I call "compromise calibers". There are a couple in between the maximum ends of the debate and recently that has been thrust into my consideration almost against my will.

What I refer to as Compromise Calibers includes anything that is between the 9mm and the .45ACP is size (10mm, .40S&W, etc) or a production caliber (as compared to a custom-only wildcat cartridge) that changes the basics of either such as the .357Sig or the .45GAP. Arguably the first compromise caliber (in a pistol) was the 10mm presented in the early 1970s, but before we get into that, let's talk a bit about the compromise being made.

Way back when the U.S. Military discovered that the .38 caliber bullets they were firing from their revolvers were not delivering incapacitating injuries to the enemy. That's not to say that the injuries weren't fatal - just not immediately so. Of course, 100 years later we have thoroughly documented (now) that an injury isn't immediately fatal unless it hits the Central Nervous System (brain or spinal cord) and even then, if it's a spinal cord shot it may only be incapacitating, not immediately lethal. That's why our bullet designs and caliber / velocity pairings focus on doing as much damage as possible to large blood-bearing vessels and organs so as to cause the enemy to bleed as much as possible as fast as possible to shut down their system. In other words, we cause injuries that make them bleed to death (or close to it).

Now, I know that police officers and deputy sheriffs and every other variant of law enforcement professional in the country today doesn't shoot suspects with the intent of killing them (and if you did, you'd be a fool to admit it). Instead, you deliver shots to the center mass of the suspect when justified in an attempt to incapacitate them as quickly as possible thereby stopping the threat to you, your partner and all bystanders in the area. That's your job. Writing for soldiers can often be easier: soldiers kill the enemy. That's what they do. "Overkill" is a political term of concern. Screw that. I used an AT-4 to stop that enemy truck? Yeah? The problem is? My booby-trap had two grenades instead of one which would have been sufficient? What's your point? You get the message. Law enforcement has to be far more careful about what they write and say. That means that the people who design ammo and weapons also have to be careful what they say in sales pitches.

Keep all of that in mind as we discuss a few compromise calibers, focusing down on one, and the pros / cons to be had.

So the compromise is a balance sought between carrying as many rounds as we comfortably can of a caliber that will do sufficient damage to the enemy or suspect when necessary and deliverable from a firearm that can be conveniently worn or carried. Agreed? Cool.

As we've identified the 9mm and the .45ACP as the genesis of this debate if you will, let's talk about them briefly. Both created before 1900 and both packaged in relatively concealable carry packages (i.e. the Browning High Power or the Government Model 1911), they offer a choice:

Do I want to carry more rounds of a smaller caliber bullet that exit the barrel faster?
or do I want to carry fewer rounds of a larger caliber bullet that exit the barrel slower?

Remembering Einstein's formula of E equals M times C-squared, we have to admit that the smaller faster bullet can deliver an equal amount of energy as the bigger slower bullet. In fact, if engineered precisely, they could deliver an exactly identical amount of energy. But is it all about energy? We all already know it's not. As we said earlier, when stopping the aggressive action of the opponent, the goal - short of a central nervous system (CNS) hit - must be to cause sufficient damage to create a quick drop in their blood volume so that they drop.

Simple logic - with a focus on simple - would dictate that a bigger bullet makes a bigger hole and therefore does more damage. The challenge with that simple logic is that terminal ballistics have proven less predictable than we originally thought they would be. Bullets traveling faster than 1,000 feet person second do some strange and unexpected things upon impacting flesh. Hollow point, jacketed bullets sometimes don't expand as they are designed to do; other fragment for no observable reason. In other words, quite often our high-tech science does little more than allow us to take a good guess at what the bullets will do. In field terms we call this a "WAG" or Wild Ass Guess. In more specific and technical terms we call it a "SWAG" or scientific wild ass guess.

Past history shows us that people can die from being shot with a .22lr bullet. Countless hundreds of thousands have been killed by .223 / 5.56mm bullets. Velocity certainly plays a part along with multiple round delivery. There was a time when we had to separate the arguments between rifle calibers and handgun calibers, but with some effective rifle cartridges now packaged in handguns (i.e. the FN 5.7mm) the lines get more blurry than ever.

As we said earlier, the debate has long primarily been between 9mm (or equivalent such as .38) caliber weapons and .45ACP weapons. In common handguns today, if we're arguing capacity then the argument is small. For instance the Glock Model 17 holds 18 rounds of 9mm (17 in the magazine plus one in the chamber). The Glock 21 holds 14 rounds of .45ACP (13 +1). Is the debate really going to rage over FOUR rounds of capacity? If you are a fan of the .45ACP but want a higher capacity and so you switch to the 9mm to gain FOUR rounds, don't you think you should probably re-assess your shooting skills?

For decades the U.S. military found eight rounds (7+1) of .45ACP in a Government Model 1911 pistol sufficient. For most of those decades law enforcement found 6 rounds of .38 in a revolver sufficient. With two magazines for backup in the 1911 you had a total of 22 rounds of .45ACP. With two speedloaders for your .38 you had a total of 18 rounds. Certainly there were instances of officers and soldiers feeling under-gunned or citing examples of how those weapons and/or cartridges failed. There are also hundreds of stories about how well those weapons and calibers performed. 1985 changed it all. The debate wasn't settled but it was certainly quieted when the U.S. Military adopted the Beretta M9 9mm pistol with its 15+1 capacity. Adopted by the military and picked up by law enforcement agencies across the nation, the Beretta M9 or the civilian variant Beretta 92F seemed to silence the 9mm vs .45ACP debate. Maybe...

But there were still plenty of people out there who weren't confident that shooting someone with a 9mm round would provide sufficient immediate (or as close as possible) incapacitation. Other options were sought. That same year the .40S&W was born. Evolving out of the 10mm as the load was developed and changed in accordance with FBI requirements, the .40S&W cartridge ended up the same overall length as a typical 9mm Parabellum round. Since .40 and 10mm equal, the difference in diameter was only 1mm. Could it really make a difference? Apparently so. People and law enforcement agencies flocked to the .40 in untold numbers. In some pistols the change from a 9mm to a .40S&W caliber design didn't mean huge scrifices in capacity. Again, the Glock 17 9mm with its 18 round total capacity was compared to the Glock 22 .40S&W with its 16 round total capacity. Would those two rounds really matter? Many said no.

Then came compact and sub-compact models of .40S&W pistols. My latest venture into this arena is the Beretta 96F Centurion with its 11 round total capacity. The shorter slide, barrel and frame as compared to the Beretta 96F make the 96F Centurion easier to carry and conceal. However, since it's a .40 caliber weapon I hardly feel like I'm carrying a "mouse gun".

It's my opinion that the .40S&W is the ultimate compromise cartridge. It's small enough in diameter to load plenty of rounds into double-stack magazines, but it breaks that psychologically meaningful barrier of a caliber that starts with a "4" instead of a "3" or anything equivalent. That said, now I have to select between my carry guns from amongst my:

  • Glock Model 19 with its 15+1 9mm capacity, or
  • Beretta 96F Centurion with its 10+1 .40S&W capacity, or
  • Springfield Armory 1911 with its 8+1 .45ACP capacity.

The difference between the 9mm (16 rounds total) and the .40S&W (11 rounds total) is the most extreme. The difference between the .4S&W (11) and the .45ACP (9) doesn't really seem worth arguing about, does it? Then my thought is this...

Is it really worth arguing in the first place? Probably not. If you're a fan of and comfortable with the .45ACP weapons, carry one. If you prefer and are comfortable with the 9mm, carry that. If you like the .40 because it makes you feel like you've solved a difficult conundrum, then carry it.

Me? I still make a choice every day based on how I'm dressing and where I'm going. Variety is good. Don't pick just one. Have one of each available and make your choice as each set of circumstances looms.

Stay Safe!


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