Cartridge of the Week, the .45 ACP, .45 Auto

This week we look into the American classic cartridge, the .45 Automatic Colt Pistol. John Moses Browning, who some may consider the finest gun designer of all time, conceived the cartridge in 1905. It entered service as part of the most iconic pistol of the 20th and 21st centuries, the Colt 1911 and 1911A1. It is hard not to tell the story of this cartridge without some brief notes about the 1911 platform, as they are synonymous. The legendary pistol comes in many packages from many manufacturers. This was especially true in 2011 during the 100-year anniversary of the gun and the .45 ACP.

Browning based the .45 ACP on the black powder-era idea that an effective cartridge does not have to be fast as long as it is big. The cartridges of the black powder era were mostly small pistol rounds or heavy calibers like the .44, .45, .50, .60, and beyond. However, these flying ashtrays acted more with the effect of a mule kicking you in the chest than a hot poker going straight through you. Shock waves and kinetic energy transfers came from non-excessive penetration, resulting in the projectile dumping all of its energy into the target. This dumping of energy made these black powder calibers physically devastating to their targets.

The introduction of the .45 ACP to the battlefield came in 1911 during the Moro Civil War of 1899-1913 in the Philippines. This cartridge proved to be a valuable weapon for the United States military. The .38 Special cartridges were sorely lacking in stopping attacking enemy troops armed sometimes with only machetes. Small-framed Moro’s would charge the U.S. troops armed with their razor-sharp instruments. Hit with multiple rounds of .38 caliber ammunition, they could continue onward despite their wounds. Some pictures still exist of them proudly displaying their gunshot wounds. It is fair to say that some of this ammo was very underpowered. Some of the cartridges were still loaded with black powder, which offers far less pressure than smokeless powder. This action, along with other factors, compelled the army to call for a new self-loading pistol cartridge with greater power. They specified that they wanted their new cartridge in .45 caliber, and John Browning delivered.

On October 8, 1918, a young Corporal Alvin York and his unit were under attack from a large contingency of German troops. He, with bayonet fixed on his rifle, made it to the opposing trench under machine gunfire. Upon reaching the opposing trench he was out of ammo in his rifle and drew his 1911 .45 ACP and killing six German troops who began charging him, all this time while being fired upon by a German officer. York, along with seven accompanying U.S. soldiers, captured over 130 German soldiers and with his pistol and seven comrades marched them back to U.S. lines as prisoners. No one would ever doubt, as he received the Medal of Honor, what one motivated soldier could do with a gun equipped with this powerful cartridge.

The cartridge would then see battlefields in the Colt 1911 and the 1911A1 upgrade during World War I, World War II, Korea, Vietnam, the Gulf Conflict, and many excursions in between. The .45 ACP was and still is the preferred caliber of the famous Texas Rangers and many U.S. soldiers. We also see it wore a black hat as well as it was the nemesis of law enforcement.

The .45 showed its dark side during the prohibition era. From 1920 to 1933, it was the choice round for the famous Thompson submachine gun. Designed by American John Thompson, it became the weapon colloquially referred to as the Tommy gun. In its early days, this handheld machine gun could deliver up to 600 rounds of .45 ACP per minute. Following its maturation period, it could deliver up to 1,500 rounds per minute. Ironically, lawbreakers and the FBI would be shooting at each other with the same bullet, as it was the best there was for the guns of the period. This cartridge came of age not on the battlefields of Europe but on the streets of Chicago and other dangerous U.S. cities.

Through wars, crime, time, and trials, this cartridge has stood the test of anything a soldier, bootlegger, or competition shooter could muster. Though the U.S. military, in favor of the 9mm cartridge, retired the .45 ACP and the Colt m1911A1 in 1985, this old warhorse refuses to fade away. It has seen a resurgence over the last 10 years, especially during the 100-year anniversary in 2011. Some soldiers even resisted surrendering their .45 ACP weapons and purchased their own for individual units, making the cartridge a remaining player on the battlefield 101 years after its birth.

This is not just a bullet—it is an American icon. It is so iconic that it is almost a symbol of strength and power, good and bad. Like many of the inventions of John Moses Browning, it may go another 100 years.

I’d like to spit some Beechnut in that dude’s Eye
And shoot him with my old .45
Cause a country boy can survive
Country Boy Can Survive words by Hank Williams Junior 1982

Black bandanna, sweet Louisiana
robbin’ on a bank in the state of Indiana
She’s a runner, rebel and a stunner
On her merry way sayin; baby whatcha gonna
Lookin’ down the barrel of a hot metal .45
Just another way to survive

Dani California words by RED HOT CHILLY PEPPERS 2006


.45 ACP Ballistic Comparison
Cartridge  Bullet Weight Muzzle Velocity Muzzle Energy
.38 Special 125 Grains 950 fps 251 ft.-lbs.
9mm Luger 124 Grains 1,120 fps 345 ft.-lbs.
.45 ACP 230 Grains 850 fps   370 ft.-lbs.
.40 S&W 155 Grains 1,205 fps 485 ft.-lbs.
10mm 155 Grains 1,330 fps 605 ft.-lbs.


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Comments (8)

  1. Good article except the round used in the Philippines was the .38 Colt, and not the .38 Special. None the less, the slightly more powerful .38 Special round would not have been any more effective against the drugged up Moro natives. The first effective substitute was to reissue revolvers in .45 Colt, which got the job done until the 1911 was produced and the US Army entered the semi-automatic age.

  2. Great article. Glad it was listed under a current one so I could find and read it.

    My wife (who loves guns and shooting) immigrated from Austria about 5 years ago, so I very much enjoyed showing her the pictures and reading her the article. I also enjoyed explaining how the 1911 and Ma Deuce are still in service every day all over the world. She loved it, especially Sgt. York since she hates Europe, and Germany and Austria especially. 😉

    As for John Browning and the .45, he is a man I admire for his creativity and the profound impact on firearms he had. A brilliant man. The .45 ACP is my favorite pistol round and I am happy to own a 1911, Glock 21 and XD45.

    Of course, my wife prefers her Beretta 92, which to be fair is another iconic firearm. Yeah, I have one too.

  3. Funny you should run this article about the .45 I was looking at website and they had a .45 ACP Peters Shot Shell for the Thompson Machine Gun. Has a paper/cardboard cover instead of a bullet and is a little longer than the usual .45 auto round. Needed a special magazine to use in the Thompson. I bought one of these rounds at a gun show this year. This was used for police riot control.

  4. can someone help me with some information on a sgt alvin york collectors edition colt 45. was told there were only 300 made trying to verify authenticity but havent had much luck finding info or pictures

  5. i’d like to see the old ‘flying ashtray’ (200gr federal?), whatever it was, redone to the exact orig. specs., BUT w/ a nylon-feed-ball in the cav. to prevent the feed-problems of the orig.; also, somebody like Glock do a reasonably priced .460 Rowland, but w/ a longer slide-stroke to take up some more recoil: use the idea of the telescoping r. spring of the short-slide Glocks in a 5″ bbl-slide Glock; also progressive-strength r. springs; also somebody needs to do a .45/.460 sabot to .357, e.g.; also somebody needs to re-invent the ww2 taper-bore idea, so a .45 tapers down to a .357, e.g. swaging a .45-sabot down to a .357-sabot; these do give a big velocity boost in other apps.

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