.45 ACP Complete Guide: History, Ballistics, Applications, & More

.45 ACP Complete Guide: History, Ballistics, Applications, & More
July 19, 2022 Edited March 28, 2023 3484 view(s)
.45 ACP Complete Guide: History, Ballistics, Applications, & More

First, let me say one thing before we even start… the old .45 ain’t dead. To paraphrase Mark Twain, the reports of its death are greatly exaggerated, certain YouTube “shooting experts” notwithstanding.

The .45 ACP (Automatic Colt Pistol) cartridge burst upon the scene in 1904, the year of the St. Louis World’s Fair (watch Judy Garland’s 1944 Fair-based “Meet Me In St. Louis” for a laugh and a tear). The .45 ACP lagged three years behind Georg Luger’s 9mm cartridge in terms of birthdays but took off when it finally saw the light of day. John Moses Browning perfected it to run in his newly-designed Colt semi-automatic pistol, the Model of 1905. Here’s a bit more history…

 

.45 ACP’s Story

The Moro rebellion in the Philippines around the year 1898 wasn’t going so well for our home team. The U.S. Army was tasked with putting down that rebellion but had run into trouble stopping Moro tribesmen with their issue .38 Long Colt revolvers. The Moros would get high using naturally-grown pain-masking narcotics, then would wrap themselves in an armor of sorts made up of tightly-wound thick grass and other vegetation.

Charging at our troopers, the grass would slow the .38’s already-lethargic bullet, and the effects of the drug would lessen the feeling of pain. The upshot was that many were upshot… er, shot up, several times, to little or no effect. They would keep coming and then behead or otherwise nastily deal with our troopers before succumbing to the effect of the .38s’ rounds.

This caused the Army to reissue warehoused 1873 Single-Action Army revolvers. The .45 Colt round did the trick… grass and “grass” or not, the tribesmen were finally dealt with. The Army knew it needed to come up with something different in terms of sidearms.

 

Enter Thompson and LaGarde

Spurring John Moses on to finalize his .45 semi-auto round were the Thompson-LaGarde tests of 1904 . After the dismal performance of the .38 Long Colt in the Philippines, the Army tasked Colonel John T. Thompson of the Infantry and Major Louis A. LaGarde of the Medical Corps with developing a more efficient stopper for the military’s handguns.

They performed all sorts of tests on cattle (and a couple of horses, I’ve read) to determine which of the test rounds caused the most trauma and dispatched the test animal the quickest. Calibers tested included:

  • 7.65×21mm Parabellum (.30 Luger) and the 9×19mm Parabellum (the familiar 9mm Luger (Germany);
  • .38 Long Colt, .38 ACP, and both blunt and hollow-point .45 Colt (US):
  • .476 Eley and the “cupped”.455 Webley (UK).

The tests were not overly scientific but did yield results, After many trials, the two concluded that the new military round should be of no smaller diameter than .45 caliber and be made to function in a semi-automatic pistol.

That was huge for the time – revolvers ruled. Originally loaded with a 200-grain bullet at 900 f.p.s., it was later modified to shoot the familiar 230-grain round-nose FMJ bullet we all know and love (the “punkin ball”) at a nominal 850 f.p.s.

Old 45 ACP bullet with white background 45 acp bullet drawing with dimensions

(I just referred to this bullet as a “punkin ball”. That’s because I’ve called it that for more years than most of you are old. I’m not sure where I picked that up, but I imagine it was from another .45 Auto shooter…)

Things hummed along after the Thompson - LaGarde tests. The Army needed a new pistol from which to shoot the military’s new round. The Model of 1911 was adopted after military trials in that year.

M1911 A1 Handgun

M1911A1

I won’t go through that history, since we’re looking at the .45 ACP cartridge and not the pistol that made it famous. For 74 years, from 1911 to 1985, the .45 ACP and the M1911 was found in U.S. military holsters worldwide. It was then, in 1985, that our military decided to adopt the NATO standard sidearm (pistol) cartridge, the 9mm (or 9x19).

Even so, we still will see some pretty highly-developed 1911s in use by some of our special forces. Also, it is a favorite among civilian concealed carriers. Once upon a time, it was considered King of the CCW crowd back when most 9mm loads consisted only of an FMJ bullet at around 1100 f.p.s. out of a full-size gun.

Given the bullet technology changes that have been applied to the 9mm making it more effective, the .45 ACP is nowhere near as popular as is the 9mm now. That, however, hasn’t stopped hundreds of shooters from sending thousands of “punkin balls” downrange!

 

Ballistics

Let’s face it – the old .45 isn’t known for its laser-straight bullet trajectory. The cartridge was initially designed to be used by troops at ranges no further than 50 yards. It gained a reputation as having a rainbow path to the target when some shooters insisted on trying it at 100 yards or more. This wasn’t in its original portfolio and is not a fair assessment. Here is a chart from shooterscalulator.com that illustrates this:

45 acp ballistics chart

The above chart is for just one variation of a generic .45 ACP load. For a more complete discussion of .45 ACP velocities that involves testing many different loads, check this out – you will most likely be able to find a load or two that would meet your criteria in terms of ballistics for the old warhorse.

Bear in mind that most recreational .45 ACP shooters will zero their guns at 25 yards, which will put them 1.6 inches low at 50 yards. These figures are for the 230-grain FMJ ball round (my “punkin ball”) and would be different with a lighter bullet or a different velocity. I’m trying to keep it simple.

 

Stopping Power

What about that “unicorn” topic of caliber wars, stopping power? I almost hesitate to touch on this grail subject, since it is so hard to define and even harder to prove. We could talk about the percentage of the time that a certain caliber enabled a one-shot-stop… here is an interesting read on that.

You could do a Google search on the topic and come away with many articles and other pieces written about it. The most authoritative, backed-by-data expositions usually involve one or all three of these names: Evans, Marshall, or Sanow. These guys have studied data from thousands of shootings and have compiled some pretty interesting statistics.

Without turning this into a treatise on said topic, I’ll suffice to say that the .45 ACP comports itself well and is usually “up there” in terms of an effective caliber. But… with modern loadings, it’s about equal to the 9mm and .40 S&W in effectiveness. This is not to put it down… it works, with around 400 foot-pounds of energy for most popular self-defense loads.

It’s just that many who carry a pistol for defense will opt for the 9mm since it is statistically close to the .45 in one-shot-stops and tends to be used in guns with higher-capacity magazines (8 or 10 .45s vs. 13 – 17 9mms). It’s also lighter to carry – weigh a box of 50 .45 ACP 230-grain loads, and then weigh a 50-round box of 9mm 124-grain loads. There is a difference.

 

.45 ACP vs. 9mm (Target Disruption)

OK, I hear you thinking “What is target disruption!?”. Let me explain. Certain things happen when a bullet hits its target. I don’t mean a steel, or even paper, target but one of the adversarial sort – the two-legged predator that demands your wallet or worse after pulling a knife or gun.

Two schools of thought have existed for decades on the best way to put down such a threat. One is the light-bullet-high-velocity school. A major proponent of this was Lee Juras, back in the ‘60s and ‘70s. His Super Vel company, headquartered not too far from where I live in Indiana, produced ammo for handguns that used very light bullets at ridiculous velocities to induce a type of hydrostatic shock when the bullet met soft tissue.

I’m not sure if any bullet at handgun velocities can truly, effectively induce that form of upset in a human being, but his ammo was popular. They are in business today but seem to sell remanufactured ammo for training purposes and not the barn-burners of days gone by.

The other theory of stopping a threat is the “slow-speed-high-momentum” school of thought. That is where the original .45 ACP load fits. The idea is that a target can be taken down readily by a large caliber, heavy bullet that expends all its energy in the target as opposed to punching through it and zipping off to parts unknown.

The British subscribed to this theory, as is evidenced by their .455 Webley revolver, among others. This loading used a 265-grain pointed round-nose bullet at around 700 f.p.s. If it got past heavy coats or other barriers, it was fairly effective.

Gun guru Jeff Cooper described, in print, the working theory behind this type of load. He used, as an example, closing a heavy safe door. He said if you whack it with your hand in an attempt to close it, all you will do is hurt your hand and the door won’t move much. But, if you give it a good, strong slow push, it will close.

He likened bullets and loads (light/fast vs. heavy/slower) with that analogy. We must remember that he was perhaps the nation’s main 1911 proponent when he was teaching and writing back in the ‘60s and ‘70s. I have, somewhere in the disorganized chaos of my garage a copy of his “Cooper On Handguns”, written in 1974. (If you get a chance to pick up a copy of that revered tome, please do. It is still viable today).

He liked the 1911, and (incongruently) the CZ75. I didn’t understand at the time why he liked the Czech pistol, but as I got older and more experienced, it made more sense. Anyway, he had a point with his safe-closing analogy. I will leave it to you, dear reader, as to which school you identify with. Both have their advantages.

45 ACP vs 9mm

 

Applications

So why would you want to buy a .45? There are several reasons to shoot .45 pistol … or carbine.

Self-Defense

At the top of the list is self-defense. There are dozens of loads out there now that will reliably expand a JHP or JSP bullet at .45 velocities. This is not to mention the fact that the old “punkin ball” did pretty well throughout its 70-plus-years in our military’s 1911s. With the advent of expanding bullets, the .45 came into its own. In terms of effective .45 ACP ammo, we might include the following loads:

Federal HST 230-grain

Winchester Ranger 175-grain Frangible +P

Speer 155-grain Lawman RHT - very light-for caliber frangible round

Hornady 230-grain JHP XTP +P

Remington 185-grain Golden Saber Bonded

These are just a few of the many loads out there that work. They expand on the typical representative bullet weights popular in the .45 ACP (185 - 230 grains). Do some experimentation on your own to see what works best for you.

If you don’t have ballistic gelatin, you could try what I’ve done in the past… the redneck penetration test media, your garden. I’ve shot into tilled soil in the days before ballistic gel was broadly available. I’ve gotten relative comparisons between loads before in terms of penetration and expansion. This is not the recommended method of course, but it works if you just want to see if a bullet will expand at all.

The above are some recommended self-defense loads, but here’s another reason to shoot a .45…

45 ACP bullets with white background

 

Competition

One popular form of pistol competition is IPSC (International Practical Shooting Confederation). If you want to make the IPSC Major Power Factor of 170, the .45 ACP is right up your alley. The caliber has been used by IPSC shooters for decades because of that Power Factor thing. It's also a must in the Heavy Metal division of 3-Gun competitions.

There are very few .45 loads that won’t hit that mark. Of course, other calibers can qualify as Major as well… the .40 S&W comes to mind and even some less-well-behaved 9mm loadings. It’s just that with the old .45, you’re pretty much assured of making it.

But what if you are ringing steel? Steel Challenges are often the home of light 9mm loads which allow for speed and accuracy without much recoil. I would still venture to guess that many steel shooters use a .45.

Why? Well, I think the main reason is that if you hit the plate, you KNOW you’ve hit the plate. There’s no doubt about it. That 230- (or 200-, or 185-) grain bullet spanks the steel, unlike other bullets from some other calibers. For that reason, it is very popular among steel-smackers.

Lastly, go on a short journey back with me to yesteryear when bullseye competitions flourished. A shooter had a rimfire and centerfire gun with which to compete. (Some shooters used two different centerfire guns). Shooting at round bulls-eye-type targets, you had just so much time to fire your strings. The .45 ACP sufficed as the centerfire pistol for many shooters as the larger .45 bullet cut a bigger hole than a .38 Spl. could.

That gave it the possibility of touching a higher-scoring ring. Here’s an interesting fact… a common practice at the the time involved sticking your support hand in your pants pocket and standing almost sideways as you lined up your sights on the black bullseye. You put only one hand on the gun.

This sport was one of the most popular shooting events in the 1950s but lost popularity to more action-styled shooting matches and was fairly dead by the mid-’80s or so. It has experienced a revival of sorts in recent years, so you might be able to find a match near you. At least go watch one to see how it’s done – you might get hooked!

Competing Shooter Using a 45 ACP Handgun

 

Plinking/Reloading

The .45 is not generally thought of as a plinker, but if you add reloading into the mix it becomes eminently doable to spend an afternoon at the range, pasture, or another informal shooting venue. I can’t tell you how many hundreds, if not thousands, of my home-cast lead bullets I’ve stuck into paper target backstops over the almost 50 years I’ve reloaded for the .45. I

like Lee bullet molds – they’re easy to use, are fairly inexpensive, and yield good bullets from the get-go. I’ve shot enough 200- and 230-grain bullets to fill at least one bathtub, I think. I had fun making the bullets, had more fun reloading them, and even more fun shooting them. I do not hunt with the .45 ACP – it’s not deer legal in Indiana – but I have killed many deer over the past 40 years or so with my S&W 629 long-snouted .44 Magnum or my Ruger .45 Colt Blackhawk. Reloading and bullet casting are topics that deserve their own articles.

No matter how you use it, the .45 ACP is versatile (I have a .45 ACP cylinder for my Ruger Blackhawk), and is a reliable round that is easy to shoot, easy to reload, and easy to find.

45 ACP shot on range

 

.45 ACP Carbines

Want a carbine in this caliber? There are many made, with more on the horizon from Bear Creek Arsenal (can't wait)!

The round comes into its own in a carbine – that 230-grain bullet at 850 f.p.s. Out of a 5-inch barrel is one thing; move it out around 1000 f.p.s. out of a carbine and that will get your attention!

You gain almost 200 ft./lbs. of energy over that produced by a 5-inch pistol barrel. That puts it up into the .357 Magnum class, which in all practicality is enough for close-in deer… but it’s still illegal (at least here). Check your state’s hunting regulations.

45 ACP Bear Creek Arsenal Graphic

 

Conclusion

If you are looking for an addition to your gun collection, consider picking up a .45 ACP. You can find everything from an inexpensive, imported 1911 through Glocks, all the way to the Sig P220 that the Indiana State Police carry (in .45 ACP, of course).

I like old things. Heck, I am old. I even like revolvers, of all things… don’t hold that against me. I’ve used the .45 ACP for over 4 decades with generally excellent results. Don’t you think it’s time you launched a few “punkin balls” towards the target? Let us hear of your experience with the old war horse below!

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Kyle Tighe
July 20, 2022
It would be bad a** if BearCreek put out a 45acp uppers with mag adapters and or dedicated lower receivers, also maybe considering 10 mm would be fantastic as well it is my favorite caliber after all
Brett
July 21, 2022
Yes! Yes! 45 ACP Uppers. Let's do this. Love Bear Creek. I take a little credit for this because I've messaged them twice now telling to make 45 ACP uppers. Thanks for listening BCA!
Lucas
July 22, 2022
Would be a great time to release your line of suppressors at the same time...
Jason Martin
July 23, 2022
FINALLY! I've been begging BCA for 2 years to build a G2 .45acp! My dream AR! A Tommy Gun on steroids! Now how about you guys start making slick top handguards like the Sig Tread handguard for hunters especially with the public stigma right now concerning AR'S. A slick handguard is not as " threatening " to small minded people today,to test this idea I ground off the entire Pic rail off a old 10" BCA handguard & repainted it ,& even though it's on a 10.5"barrel AR "pistol " with a sba3 brace it doesn't draw near the attention at the range opposed to a standard BCA handguard! Also got tons of people that wanted a slick handguard for their AR- still have plenty of attachment points with the mlock- just way cleaner! Help us out guys!! Capt J
Terry
August 4, 2022
Agree completely on carbine .45's. I used to have a semi-auto Tommy Gun. I experimented with loads to give better accuracy at longer ranges. I found that Blue Dot powder really took good advantage of that longer barrel, and proved very accurate at ranges you wouldn't normally expect a .45 ACP round to do well at. As for stopping power, I knew of a former Navy Shore Patrolman who worked as a guard in a warehouse. He carried a 1911 as a service firearm. One night, a burglar broke in. The guard ordered him to halt, and the guy charged him. The guard ended up emptying his mag into the guy, center of the chest. The burglar lived long enough to reach the guard and get his hands onto the guard's throat. Turned out, the burglar was high on PCP. That being said, my carry firearm is a 1911 Officer's model.
Raymond Clark
August 15, 2022
1911 variants in .45ACP is the only sidearm I will carry. goes back to my Marine Corps days. I am impatiently waiting for BCA to get their .45ACP to market so that I can add it to the 3 other BCA calibers in my inventory. Just wish they offered more calibers in left side chargers.
Gregory Simmons
August 18, 2022
Dear Santa, All I want is for Bear Creek to make a 45 ACP upper. Well maybe bring gas and ammo prices down too. Thanks
Paul
January 26, 2023
Just make that .45 ACP the people have spoken. Thanx BCA for all your products.
Gary Walls
March 16, 2023
I want one
Kenneth Wegman
March 16, 2023
Count me IN for one with a Glock magwell!…40 or .45 will do.
Douglas Auman
March 18, 2023
Just a question. Could I adapt the S&W Xd 45 mag to fit?
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