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45 Long Colt (vs 45 ACP)

The .45 Colt is often confused with the more common .45 ACP (also called .45 Auto) cartridge. While similar in some respects, they are not the same. The confusion often stems from the fact that ACP stands for “Automatic Colt Pistol”. The .45 colt is also called the “45 Long Colt” or can be shortened to “45 LC” to help differentiate it from other rounds.

History of the .45 Colt

Colt Firearms Manufacturing Company Logo

The colt 45 cartridge is a somewhat older round: it was first developed in 1871 by Colt to meet a government need for a revolver that fired a self-contained cartridge. At the time, the development of a revolver for government use was an attempt to bring the army into the future.

Keep in mind the historical context here: in the not-so-distant civil war, most of the firearms in use by government forces were black powder firearms that were variations on a musket. By the end of the war, the revolver had been invented but was not yet in wide government service.

45 Colt Bullet Cartridge

Technological Development

In the years after the civil war, the US government saw the need to replace single-shot sidearms for their soldiers and began to look into other options. At the time, many a county sheriff would have riled upon a revolver as a primary weapon: being able to use cartridges that come in a box, and be able to shoot them relatively quickly led to the quick introduction and adoption of revolvers, and the army began to pick up on that knowledge.

By 1873, the army had purchased both the .45 Long Colt round and the accompanying Colt Single Action Army Revolver (also called “Colt Peacemaker”). With these, the army replaced guns that fired a single round. These new Colt Model 1873 revolvers featured six rounds and operated in single action: you had to cock the hammer between each shot. Even though this is considered slow today, this Colt design not only solidified the company, and Colt’s own personal career, in the lexicon of history, but also introduced the world to the revolver, making the .45 Colt a major landmark in the slow transition from muskets to, by the 20th century, smokeless powder and semi-automatic firearms.

Place in History

Once the Colt 45 entered production, it became, in many ways, the major symbol of the government in the American West. Whether in the hands of a local sheriff or the army, revolvers firing this cartridge were used in the struggles for power (often on multiple sides) in the American West. This cartridge, fired in revolvers that had a lot of firepower for their weight, gave people heading out into the relative unknown a little more confidence.

The Colt Single Action Army revolver was used by multiple countries in many wars throughout history including the American Indian Wars, the Spanish-American War, and even WWI and a bit in WWII.

When Samuel Colt invented the round, he did a lot more than invent the 45 LC to meet government needs and further his career: he invented an object that would still be a part of the American conception of a historical period for years to come. It’s hard to say how many Colt 45’s were sold and supplied during this period, but we do know that even today, this page in American history is, in popular culture, defined by a cowboy with a hat on his head and a colt pistol on his hip. In this regard, the .45 Colt was the round that made the revolver popular, and cemented the historical place of Colt.

Colt Single Action Army Revolver
A .45 Colt Single Action Army Revolver issued in 1877 to the 7th Cavalry


The .45 Colt is also sometimes called:

  • .45 Long Colt
  • .45 LC
  • 11.43×33mmR

Not to be confused with the similar 45 ACP (also called 45 auto).

Uses For the .45 Colt

Reenactment of an old town cowboy shootout with the sheriff

Historical Reenactment

If you want to get into cowboy action shooting, or simply like the historical period, I can think of few better ways to refer to the aforementioned historical period than to slap a cowboy hat on your head and to get a 45 colt pistol, preferably either a Single Action or a good reenactment.

For this, you do have to be a little careful with ammo. While the 45 long Colt is an old cartridge, not all ammunition is the same. There are several good manufacturers that make historically correct loadings that are just fine to shoot out of a Colt Single Action. The random guy at the gun show, though, might well make cartridges that will fit in your old revolver but might well be loaded with modern powder that will cause massive damage.

A revolver in .45 Colt is one of the critical pieces to a historical reenactment of the old West, and thus if you’re into playing cowboy one way or another, we think that this one of the best ways to use Colt 45. With that said, we are distinctly glad we don’t have to use one of these revolvers in a last stand against a much larger force of extremely determined folks.

Practical Shooting

When compared to modern handgun and rifle cartridges, this old colt cartridge isn’t exactly the most powerful ammo deal that’s getting sent to your email inbox every day. With that in mind, for a period of several decades, it was a more than competent cartridge for self-defense and the kind of work that would often require using a firearm plenty of the time.

To be clear, we don’t think that we would choose a revolver in this caliber for home defense in 2022. But, if you had to defend yourself and no help was coming, then having a revolver in 45 colt would certainly be better than having to fight an intruder hand to hand when you could reach out and touch them with a blast from the past.

Additionally, the 45 colt is a more than capable cartridge if you plan to hunt small to medium game at short ranges. For instance, a lot of people fed themselves and their families with some combination of a lever-action rifle and Colt revolver, and we think that doing such a thing today is still more than possible if you have a passion for these kinds of historical cartridges and firearms.

Pros of the Colt 45

  • The Colt 45 is the cartridge that you will need to shoot if you want to shoot antique firearms made for that caliber. It might be a little hard to find, and little bit expensive, but if you want to shoot older firearms more safely ,then tracking down the correct loadings and chamberings will help you keep your antique firearms in good shape for years to come. As far as reenacting or simply appreciating history goes, it’s hard to beat firing period-correct ammunition out of an antique cold Revolver: bonus points if you can do so in some of the more desert areas of the US.
  • When you compare the felt recoil from, say, modern 9mm in a light concealed carry gun to an older Colt revolver chambered in 45 Long Colt, the 45 Colt feels substantially lighter recoiling even though it is shooting a much larger projectile. This makes it an exceptionally fun caliber to shoot: the large smoke clouds from black powder cartridges also add to the fun of shooting a fair bit.

Cons of the Colt 45

  • Ammo is expensive these days no matter what caliber you’re shooting, and the problem generally gets worse as you get into more niche cartridges. This is certainly true of old, black powder, rimmed revolver cartridges. Thus, shooting the 45 Colt at any volume will likely come with a substantial expense. If you plan to do a lot of shooting in this caliber, we’d very much recommend getting into reloading so that you can make more of them when you need to at fairly substantial savings.
  • Second, the 45 Colt is, in simple terms, an antique. When it comes to overall velocity and ballistic performance, it pales in comparison to 9mm, and even other somewhat old cartridges like the .45ACP to which it is often compared. Yes, it is possible to defend yourself with a revolver in Colt 45. With that said, in the 21st century, a black powder revolver from 1871 would certainly not be our first choice for defensive firearms. Revolvers suffer generally from a lack of capacity, this isn’t the most accurate round in the world, and the smoke cloud from the black powder will make self defense more difficult.

.45 Colt vs .45 ACP Comparison

45 Colt vs 45 ACP Comparison


The first major difference between the 45 Colt and the 45ACP is the type of powder that they use. The Long Colt uses black powder. This means that when the round goes off, you can also expect a large cloud of smoke that will quickly obscure your vision. If you fire off all six from a revolver indoors, you’ll likely not be able to see much for a bit. The ACP cartridge fires smokeless powder, which is the substantially more modern powder. In addition to the lack of smoke, this also allows for higher pressures and velocities out of the same size projectile.


Revolvers generally don’t have a way to hold the cartridge in place before they are fired. Thus, the Colt 45 is a rimmed cartridge: there’s a brass rim that holds everything in place before the firing prin strikes the primer and detonates the round. These work awesome in revolvers but are generally awful in magazine-fed firearms.

The 45ACP is a rimless cartridge. This means that there is no, or very little, brass rim at the bottom of the cartridge. It would fall right out of a revolver designed like ones from the 1870s, but the lack of a rim means that these stack much better in a magazine like those used in the Colt 1911.


If we compare original loadings, the two cartridges are fairly distinct. The original .45 Colt also called 45 Long Colt, fired heavier projectiles that moved slower and with less energy owing to the black powder. By comparison, the original smokeless 45ACP fired a smaller bullet faster, resulting in flatter trajectories.

There’s a big caveat here, however: modern loadings of both of these cartridges, with smokeless powder, do perform comparably to each other.


45 Long Colt45 ACP
Case TypeRimmed, StraightRimless, Straight
Bullet Diameter.452 in (11.5 mm).450 in (11.4 mm)
Case Length1.285 in (32.6 mm).898 in (22.8 mm)
Overall Length1.6 in (40.6 mm)1.275 in (32.4 mm)
Case Capacity41.60 gr H2O (2.696 cm3)26.7 gr H2O (1.73 cm3)
Max Pressure (CIP)15,900 psi (110 MPa)19,900 PSI (137 MPa)
Max Pressure (SAAMI)14,000 psi (97 MPa)21,000 PSI (140 MPa)

45 Colt vs 45 Long Colt

The .45 Colt and the .45 Long Colt are just different names for the same round. There is no difference between them. The name is often used to differentiate it from the more recently developed 45 ACP.

Best .45 Long Colt Pistols

Colt Single Action Army Revolver in 45 Long Colt

Colt Single Action Army Revolver

If you can find one, we highly recommend trying to pick up a historical, original, Colt Single Action Army. By modern standards, they’re not the best gun in the world: they’re heavy, not finished al that well, and have a mediocre trigger. With that in mind, it was a revolutionary firearm that changed not only firearms design, but also the landscape of the American West.

Assuming you can pick one up on shooting condition, have a gunsmith look it over and use only historically-correct loadings for these firearms.

Since their inception in 1872, Colt has stopped production of the Single Action Army several times from 1941-1956 and again from 1974-1976, but have been continuing producing them ever since. While modern versions don’t have the historical value of an original, they are a cool gun to own and shoot.

Heritage Rough Rider 45 Colt Revolver

Heritage Rough Rider

While shooting the antiques is always fun, it is, if we’re being honest, a little disconcerting hoping something made in 1875 isn’t about to explode in your hand. Thus, picking up a modern take on the classics, such as the Heritage Rough Roider, is an excellent option.

These modern-made single-action revolvers shoot well and come with a safety meaning that you can be much safer when posing for pictures at the cowboy action shooting matches where these pistols are the most at home. If the Colt was our first revolver in this caliber, this one would be our second if we wanted to do some more shooting.

Cimarron New Sheriff Revolver 45 Colt

Cimarron New Sheriff

Most of the time, we’re not massive fans of new things made to look old, but we’ll make an exception here. Meant to look like an old gun with a brass frame that has some serious holster war, we think this single action revolver would not only make an excellent piece to display but would also be a seriously fun range toy. Also, part of us kind of wants to concealed carry it for the sake of historical nostalgia.


In this piece, we started with the history of the Colt 45 cartridge. In its original form, with revolvers that were issued to various forces, it was one of the cartridges that remade the American West.

Now, nearly a century later, it’s showing its age and does not, in the original loadings, compare favorably to more modern defensive options.

With that said, if you do want to buy a gun in .45 Long Colt, there are awesome examples out there that can more than help you scratch the itch to eel a little bit like a cowboy.

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