9mm vs .45 ACP

Ah yes, the age old and never ending debate over which pistol caliber is the absolute best; 9mm vs .40 S&W vs .45 ACP.  In this blog post I will write about where this debate primarily originated from, and where I think it currently lies.

Back in April of 1986, the FBI was involved in a shootout with two people who had committed a series of violent crimes.  This is commonly referred to as the 1986 Miami Dade shootout.  A group of FBI field agents were severely outgunned by the two criminals.  The two criminals were armed with a Mini-14 rifle (chambered in .223 Rem) and a 12ga pump action shotgun.  There were eight FBI agents involved in the shoot out.  Four of them were armed with .38 Special revolvers, one with a Remington 870 12ga shotgun, and three with Smith & Wesson model 459 semi-automatic 9mm pistols.  Two of the FBI agents were killed in action, five were wounded, and both suspects were killed as a result of this shootout.  In the aftermath of this shootout, it was determined that the .38 Spl and 9mm pistols severely underperformed.  Specifically, one 9mm round fired by an FBI agent penetrated through the suspects car door, went through the suspects arm (severing the brachial artery) and stopped just shy of the suspects heart; this suspect was still fighting for several minutes after sustaining this gun shot wound.  As a result, the FBI quickly developed and adopted the 10mm Auto pistol round.  This round is significantly more powerful than either 9mm or .38 Spl, and seemed to be the solution to the problem of being under gunned.  The problem that arose was that because 10mm Auto was so powerful, it came with A LOT of recoil that led to a lot of agents not being able to qualify with pistols chambered in 10mm Auto.  Out of this came the .40 S&W round which was basically just a 10mm Auto round with a shorter case.  .40 S&W was quickly adopted by law enforcement agencies nation wide, and has served in this capacity for about 30 years and still does today.  

It is important to remember that at the time of the aforementioned developments in pistol cartridges, that the projectiles and propellants that were being used were no where near as fantastic as they are today.  Round nose full metal jacket (referred to as "ball" or "FMJ") projectiles were the norm, and gun powder did not burn as quickly and efficiently as they do today.  Because of these limitations, the conventional wisdom of the time (and most of the 20th century) was to either make a bigger bullet, increase the velocity of the bullet, or both. 

.45 ACP is one of the largest semi-auto pistol calibers in existence, and has been used by the US Military since World War I.  Soldiers loved how effectively it was able to stop threats with only one or two rounds being necessary to kill or incapacitate an enemy solider.  The draw back to the .45 ACP has always been magazine capacity.  The US Military's M1911A1 pistol only held 8 rounds in the magazine, and it was also quite heavy. 

Fast forward to the late 1980s and early 1990s, the US Military retired the 1911 as its standard issue sidearm, and adopted the Beretta 92FS as its new standard issue sidearm.  The Beretta 92FS was chambered in 9mm Luger and has a standard magazine capacity of 17rds.  At the time, this created a great deal of controversy as the 9mm round had been considered to be ineffective in the Miami Dade FBI shootout in 1986.  The common argument that was made (and still is) is that having 17rds of 9mm still isn't as effective as having 8 shots of .45 ACP.  It was also thought that 9mm had too great of a velocity and would not cause the terminal damage to a human threat like the much slower but larger .45 ACP would.  At the time, this was a valid argument as FMJ projectiles were the norm, and jacketed hollow point projectiles were still in their infancy.  

The above dilemma proves that there is no free lunch when it comes to picking the best pistol round for professional use and self defense.  You can have a large bullet that's proven to be effective at the expense of magazine capacity.  Or you can have a smaller projectile that's thought to be much less effective for the benefit of much greater magazine capacity. 

In my opinion, the above dilemma began to be much less of an issue in the late 1990s and early 2000s.  Modern ammunition propellants were becoming much more advanced and burned much more efficiently.  Jacketed hollow point projectiles really started to come into their own as well.  Jacketed hollow point (JHP) projectiles are designed to expand (often referred to as "mushroom") upon impact with a soft target.  This created devastating terminal ballistics, and quickly became the gold standard of law enforcement and civilian self defense projectiles.  With both of these technologies quickly advancing, calibers that were once thought of as ineffective started to take on a whole new life. 

Now with the advancement of propellants and JHP projectiles, 9mm is able to stand toe-to-toe with rounds like .40 S&W and .45 ACP with the added benefit of much greater magazine capacity and lower recoil making this a very effective round with the vast majority of law enforcement officers and civilians alike.  We can now have as much as 150% more ammunition in a single magazine, and be able to deliver very fast follow up shots in pistols that span a wide range of sizes from a micro-sub compact pistol like the Sig Sauer P365 to full size duty pistols such as the Glock 17.  

In 2007, the FBI wrote an article revising its position on the effectiveness of the 9mm round taking into consideration the advanced JHP projectiles.  FBI found that 9mm was superior to .40 S&W and .45 ACP in almost every way.  Attached below is a screen shot of FBI's 2007 findings.  If the below findings are true, and I believe they absolutely are, the conversation shifts from: "what is the most effective pistol caliber?" to "which caliber has the greatest magazine capacity for the gun I need to fill a certain roll?"  This often leads people to selecting 9mm as their round of choice for concealed carry, and also for law enforcement use.

​The last point I'd like to make on this is that regardless of the findings above, all pistol calibers are underpowered in comparison to a rifle.  Pistols are defensive weapons only, and should not be thought of as an all around offensive weapon.  Pistols should be used to buy you time to get to your rifle.  The rifle is what wins wars, self defense home invasion scenarios, responding to mass shooting incidents and all other scenarios where accurate fire superiority is needed to stop threats.  

The debate of 9mm vs .45 ACP will never end, but I wanted to bring real world findings and a bit of science into this debate to prove why I believe 9mm is the absolute best round for both concealed carry, as well as for law enforcement/professional use.