Knock ’em Down or Go Right Through ’em, 9mm vs .45 ACP

Knock ’em Down or Go Right Through ’em, 9mm vs .45 ACP

9mm vs. 45ACP

Zach Dunn

In the world of cartridges, there have been some very famous feuds.  The oldest feud that is still ongoing is between the .9mm Parabellum cartridge and the .45ACP.  It is a war that has been waged continuously since at least 1905 when the US army began the search for a new service pistol. 

Where all the shouting started

Georg Johann Luger, the famed German inventor of the Luger pistol that saw extensive service in both world wars, designed the famous 9mm Parabellum (Latin: for war).  Although the Luger pistol predated the 9mm cartridge by nearly 3 years, several different militaries required a larger cartridge before they adopted the handgun.  Luger introduced his parabellum cartridge in  9×19mm in 1901. 

The events that led to the invention and introduction of the .45ACP were slightly more colorful and complicated.  At the close of the 19th Century, the US found itself fighting the Islamic Moro tribe in the Philippines.  The Moros would engage in suicidal attacks against American forces in the Philippine Islands. At the time the standard ammunition from .38 Colt M1892 revolvers and .30-40 Kraig-Jorgensen rifles simply passed through Moro attackers without stopping them.  It was not uncommon for officers to empty their handguns into attacking tribesmen and still be killed or wounded. 

Some officers opted to carry old .45 long colt Single Action Army revolvers for defense.  The US military concluded that a new handgun and cartridge needed to be adopted.  Following the pattern of many foreign nations, the US decided that the semi-automatic handgun was the way to go.  Trials were held and six handguns from six different manufacturers were tested.  The winner was both the handgun and the cartridge designed by the legendary John Moses Browning. 

The M1911 service pistol was adopted in 1911.  It was chambered in the .45ACP (Automatic Colt Pistol), both designed by Browning in the early 20th century.  One of the handguns that 1911 had beat on the test range, was indecent, the Luger chambered in 9mm.  The .45ACP was twice the size of the smaller 9mm round.  In a time before expanding bullets and jacketed hollow points, the larger cartridge had a proven advantage in knock down power.  When fielded against the Moros during the last 2 years of the Moro Rebellion, reports from the field were glowing.

The two handguns and cartridges spared over the next century both on and off the battlefield.  Through two world wars, several smaller conflicts, in the hands of law enforcement and civilian shooters, both gained an entrenched camp of followers. 

In the 1970s and 80s, NATO countries started to move away from larger handguns and started to adopt the 9mm cartridge as standard.  The United States followed suit in 1985 with the replacement of the M1911 after 74 years of service with the Beretta M9 chambered in 9mm. Logistics played a large part in the switch.  It simplified supply and brought the US up to the same standard as its European NATO allies.  It also allowed a soldier to twice as many handgun cartridges as before.  

The adoption by the armed forces also changed the view of the 9mm with US police and civilians.  Soon police departments across the country were retiring their .38 special revolvers and 1911s and purchasing Beretta M92/M9s chambered in 9mm.  The officer who before, only carried 12-22 rounds of ammunition, now were carrying nearly 50.  This switch was interrupted in the 90s by the adoption of the .40 S&W but has seen a stunning reversal as of late back to the 9mm.  

Civilian shooters followed the Military and Police.  In the 1970s and 1980s the 9mm began to gain popularity, and with the introduction of budget handguns like the Glock 17 the purchase of 9mm handguns started to turn into a stampede.  This was coupled with a large amount of foreign military surplus handguns chambered in 9mm that flooded the US civilian market. It can be said, that the 9mm took the United States from a nation of revolvers to a nation of semi-autos in less than a decade. 

Modern Ammunition

One of the main reasons that led to the adoption of the .45ACP cartridge was the fact that militaries across the globe were restricted to full metal jacket (FMJ), non-expanding bullets because of the Hogue Convention.  Because of this, obviously, in war time a larger FMJ projectile would do more damage than a smaller one at handgun cartridge velocities.  The hollow point handgun cartridge did not become popular on the US civilian and police market until after the 1970s.

Whereas an FMJ bullet enters, and exits a body in an almost intact “ball”; a Hollow point round, in theory, will expand inside the cavity, often not leaving the body at all.  Thus, a Hollow Point can expand to twice the size of an FMJ cartridge.  The copper jacketed hollow point (JHP), which is the most common type of self-defense ammunition carried today, on expansion slices into the body with an objective to create devastating wounds but to slow down projectile speed and not create an exit wound.  Because most JHP rounds do not exit the body of its victim, it has become the clear choice for police and civilians who do not want to cause collateral damage.

Early jacketed hollow point cartridges had some clear advantages over FMJ rounds.  But they also had some massive disadvantages.  It was not uncommon for JHP rounds to cause failures to feed in many handguns, and could become clogged on entry with clothing, bone, and other debris and not offer reliable expansion, thus acting like an FMJ. Many people continued to carry Full Metal Jacketed rounds for defense because of this, thus for many years continuing the belief that the .45 ACP had the superior knock down ability.   

Modern advances in JHP bullet design have led to a cartridge that not only offers reliable feeding in handguns but reliable expansion.  Ballistic tipped 9mm rounds, especially those from Hornady such as their CritcalDefense and CriticalDuty line has at long last delivered to shooters and police a JHP round that can be used for personal defense with excellent penetration, expansion, and reliability.  It has also narrowed the capability gap between the 9mm and .45ACP.

The FBI Test

In the world that was dominated by the FMJ, especially on the battlefield, the .45ACP and larger cartridges ruled supreme. In fact, it wasn’t even a debate.  US Special Forces for decades after the adoption of the 9mm continued the use of the M1911 and .45ACP because of greater power.  Many law enforcement agencies adopted the .40 before the age of modern JHPs because of it’s perceived greater effectiveness over the 9mm.  However, the past decade has seen such advances in the Jacketed Hollow Point rounds as to cause the FBI to undertake a series of tests as to the effectiveness of handgun cartridges.  What they found has shocked the firearms community.

The FBI argues, that since the adoption of modern premium JHPs, handgun stopping power is a moot point since no law enforcement agency uses FMJs in a standard handgun.  Of all the common standard law enforcement handgun cartridges, 9mm, 40, 45ACP, and .357 Sig, all offer the same level of penetration, the same amount of damage, and the same lack of true knock down power. The .45 ACP had an ever so slight advantage when it came to wound channel. But one cartridge stood out to the FBI above the rest.  The 9mm.

With a larger magazine capacity, and significantly less felt recoil than the other cartridges, the 9mm allowed FBI agents to carry more ammunition and land more hits on target than all the other cartridges.  In fact, agents shooting the smaller 9mm shot much more accurately than agents using the then standard FBI .40 handguns. 

Similar tests have been conducted by several law enforcement agencies, police departments, and civilian shooters around the nation.  Time and again the modern 9mm cartridge is coming out on top of the classic .45ACP.  The number of accurate rounds on target and ammunition capacity has driven law enforcement back to the 9mm.  Civilian shooters as well are getting rid of their 40s and moving back to 9mm. 9mm handgun and ammunition sales have seen their largest rise in a decade. Though many who shoot .45ACP have decided to stay with the larger round. 


9mm has another huge advantage, it’s cheap.  When compared to the other big cartridges for handguns offers more rounds at a lower price.  In an age where more Americans are preparing for disasters and gun control, the ability to stack ammunition cheaply and deeply has led many shooters to the 9mm as an economical choice.  


You may also like...

Buttigieg and Far-Left: Erase Thomas Jefferson

2020 Democratic Presidential Candidate Peter Buttigieg has called for things named after President Thomas Jefferson to be renamed or erased. Buttigieg is the latest to demand the re-writing of history that the Left finds “problematic”

Russia Sells 750,000 New AK-203 Rifles

Russia has just signed a deal with the Indian Government to jointly produce over 750,000 new AK-203 rifles. The Indians have long struggled with their notoriously unreliable INSAS rifle chambered in 5.56x45mm NATO.

World War III?

What would a Third World War look like? Would it be conventional, or end in Nuclear Holocaust? Would it look like World War II, plus new technology?

Preserving and Tanning Hides

Hides have provided clothing, blankets, tools, shoes, wall decorations and scores of other things for mankind. Animal hides can provide a hunter with a fine jacket or coat, or buckskin pants that would make Tecumseh jealous.


Do you have a business you would like to promote? 1776TV is offering the chance to put your business in front of tens of thousands of visitors every week! We offer competitive advertising rates and loyalties breaks. Email us at for rates and any questions.

Conservative States Pushing Back Against The Left

Conservative States over the month of May have been pushing hard against the agenda of the Democrats and the Left. For many years it has certainly seemed to most of those on the Right that the Left was unstoppable in pursuing their agenda. May 2019 has seemingly proved them very wrong, to the detriment of the Left.

About The Author

Zach Dunn

Zach Dunn is one of the owners of 1776TV and serves as Senior Editor. He is a passionate Constitutionalist. He enjoys the Outdoors, Firearms, and History. He is a passionate follower of Jesus Christ. Zach is married to Amy and they have a son and three daughters. He currently resides in the Mountains of North Carolina.

Featured Sponsor

Advertise on

You can become a Featured Sponsor on! Support our cause, promote liberty, justice, and the American Way! Get awesome exposure by putting your business in front of thousands of like-minded, liberty-loving patriots! Learn More!


Customize Your Avatar