45 Colt vs 45 Long Colt – a 45 Caliber Debate Over Nothing

by Mike Searson
Let's set the record straight once and for all, the 45 Colt & 45 Long Colt are the same exact round of ammunition.

45 Colt vs 45 Long Colt
45 Colt vs 45 Long Colt – a 45 Caliber Debate Over Nothing
AmmoLand Gun News
AmmoLand Gun News

United States -(AmmoLand.com)- At 143 years old, a certain US made .45 caliber cartridge still shows no sign of going away. The question often becomes, “What do we call it?”

Is it 45 Colt or 45 Long Colt?

45 Colt vs 45 Long Colt History

The year was 1873 and Colt's latest handgun, the Model P (aka as the Single Action Army Revolver of 1873) was just awarded the contract as the official sidearm for the US Army. The chambering selected was a .45 caliber black powder cartridge manufactured by the Union Metallic Cartridge Company of Bridgeport, CT.

Based on the slightly older 44 Colt round, this new cartridge used the same rebated heel type bullet. It was named the 45 Colt and all was right with the world.

Two years later Army units began adopting the Smith & Wesson Schofield Revolver for use as an alternate sidearm.

Schofield Revolver .45 Colt and Others Ammo
Schofield Revolver .45 Colt and Others Ammo

This revolver was based on Smith & Wesson's Third Model top break revolver and as such offered an advantage by being faster to load and unload when compared to the Colt.

Unfortunately, the revolver used a shorter proprietary cartridge that soon created a problem of logistics. Cases of ordinance were simply marked “Pistol, 45 caliber”. The longer rounds were being shipped to units that were armed with the M1875 Schofields and the end result was that the longer rounds would not chamber in these revolvers.

The Colt shooters could easily use the shorter Smith & Wesson cartridge, so the quartermasters began referring to the Colt round as “45 Long Colt”. The Frankford Arsenal ended up dropping the longer round from production in 1887 and solely manufactured the 45 S&W round as the “.45 caliber M1887 Military Ball Cartridge until 1892 when it was replaced by the 38 Long Colt round in a new double action revolver.

For about a decade the moniker 45 Long Colt was applicable when differentiating between the two rounds but by the dawn of the 20th century the Schofield had long been retired and sold on the surplus market, by the end of World War 2, both revolvers were becoming distant memories and Colt's latest offering that proved itself in the Second World War (the M1911 chambered in 45 ACP) was becoming the new favorite among shooters.

However, after World War 2, a cultural phenomenon occurred that changed the shooting world as we knew it: Television and more specifically, programs themed as Westerns took the American imagination by storm.

Viewers wanted to own the guns shown on television, specifically, the Colt Single Action Army Revolver. Colt had ceased production at the onset of the war, but soon tooled up to make the classic revolver again and offered it in its original chambering: the 45 Colt!

After a few decades, interest in the old guns wavered again and colt retired the SAA in 1978. There was by this time a plethora of other handguns offered in this caliber from Ruger, Thompson Center and various Italian gun makers who replicated the SAA and later the Model 3. Smith & Wesson offered the 45 Colt chambering in their N-Frame revolvers as well. The round came back to the forefront in the form of the new sport of Cowboy Action Shooting in the early 1990s.

.45 Colt , A New Cartridge for a New Era

Ruger “Old Model” Vaquero in .45 colt
Ruger “Old Model” Vaquero in .45 colt

Thompson Center's and Ruger's offerings for the 45 Colt breathed new life into the old round that had eluded the older Colt revolvers and even the Smith & Wesson N-Frame. Ballisticians saw the case length and powder capacity to be the equivalent of the 44 Magnum and capable of launching a heavier bullet at higher pressure and velocity than its predecessors. These newer guns were heavier and made of superior materials than the old Colt revolvers and their Italian clones.

A few ammunition manufacturers and load developers began offering the round or the recipe to cook up a hotter load as “For Thompson center and Ruger Only” as a warning for Colt and S&W shooters to not load them in their firearms.

Do not try such loads in the Ruger “New Model” Vaquero (earlier model shown above). These guns are built on a smaller flame for competition use because the main complaint about the original Vaquero was its excessive weight compared to the original SAA and its foreign made clones.

Eventually the 45 Colt would form the basis for the 454 Casull and 460 Smith & Wesson rounds and of course the 45 Colt can be fired in these larger revolvers and single shot pistols.

The base is dimensionally similar to the .410 Shotgun round and numerous Derringers, revolvers and single shot pistols have been made to accommodate both cartridge.

The 45 Long Colt Lever Gun Myth

None of the old time rifle makers ever chambered a rifle in 45 Colt until the late twentieth century for the sport of Cowboy Action Shooting.
None of the old time rifle makers ever chambered a rifle in 45 Colt until the late twentieth century for the sport of Cowboy Action Shooting.

While it may have been popular for shooters of the Old West to tote a carbine and revolver in the same caliber, this was done with rounds such as the 44-40 and 38-40. None of the old time rifle makers ever chambered a rifle in 45 Colt until the late twentieth century for the sport of Cowboy Action Shooting.

The reason for this had to do with the case dimensions of the original 45 Colt and its almost nonexistent rim. The round was simply not suitable for use in a lever action or slide action rifle. Modern cases use a slightly larger rim, so the issue has been addressed and made logistics for Cowboy Action Shooting much easier on the participants of the sport.

So is it 45 Colt or 45 Long Colt?

While either term is correct, 45 Long Colt was really just a nickname. The majority of ammunition manufacturers stamp their cases with “45 Colt” as do the majority of firearm manufacturers mark their firearms with the same.

The reason for this is because .45 COLT is the official name used by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI). When all else fails, this is the correct term to which we fall back.

45 Long Colt Ammunition
45 Long Colt Ammunition
Mike Searson
Mike Searson

About Mike Searson:

Mike Searson’s career as a shooter began as a Marine Rifleman at age 17. He has worked in the firearms industry his entire adult life as a Gunsmith, Ballistician, Consultant, Salesman, Author and was first certified to teach firearms safety in 1989.

Mike has written over 2000 articles for a number of magazines, websites and newsletters including Blade, RECOIL, OFF-GRID, Tactical Officer, SWAT, Tactical World, Gun Digest, Examiner.com and the US Concealed Carry Association as well as AmmoLand Shooting Sports News.

  • 25 thoughts on “45 Colt vs 45 Long Colt – a 45 Caliber Debate Over Nothing

    1. First, we need to realize that firearms and ammunition manufacturers have been creating a massive variety of cartridges for well over a century. Some have become standardized and some have been adopted by various countries’ militaries. Many rounds have civilian and military designations that sound totally different, yet are dimensionally the same. Most military ammo has a feature that the civilian version doesn’t, namely crimped in primers. The feature insures reliability in full automatic firearms, as well as helping with moisture protection. Even though the .45 Colt cartridge was used as an official military caliber, at the time, mil spec was not as rigid as it is now. Today, our military wouldn’t even remotely consider using partially interchangeable ammo, as what occurred with the Schofield vs Colt rounds. The US military uses a variety of standardized ammo for basic soldiering, such as 5.56 NATO, 7.62 NATO, & 9X19 NATO. The civilian versions are .223 Remington, .308 Winchester, and 9mm Luger.
      The earlier reference to magazine fed firearms only using rimless cartridges is incorrect. The Coonan pistol was an early design that fires standard .357 Magnum ammo from a magazine. The Desert Eagle fires .44 Magnum ammo. Of course, the vast majority of box style magazine fed firearms do use rimless cartridges, with the exception of .22 Long Rifle ammo. There are dozens of types of rifles and pistols that burn .22 ammo from box magazines.
      OK, back to .45s. The caliber has been used for numerous cartridges and variants. When the .45 ACP was accepted for military service, production of pistols was slower than demand. As an adjunct, revolvers were produced in the caliber, but used special clips to function with the rimless ammo. The clips were primarily the “half moon” version, with “full moon” versions as well. They made emptying and reloading the revolvers very fast. As an alternative, a new cartridge was developed for use in the revolvers without clips. .45 Auto Rim. The case was nearly identical to the .45 ACP, with the exception of a thick rim to accommodate the moon clip design revolvers. Even though it could slide into the chambers of .45 Colt revolvers, the thick rim blocks rotation of the cylinder.
      Of course there are exceptions to the rules. A revolver was designed to fire 9mm Luger. The case mouth held the round against a ridge in the chamber and a special ejector rod had retractable fingers that tipped out to engage the extractor groove and push the empty cases out of the chambers.
      Ruger has produced convertible cylinder revolvers in several calibers. They make the Single Six convertible in .22 Long Rifle plus .22 WMR in a second cylinder. The Blackhawk has been produced in .45 Colt plus .45 ACP in a second cylinder.
      Lastly, but not least, the practice of having a common caliber in both handgun and rifle is quite old. Typically, the rifle is chambered in the handgun caliber, but nowadays it’s possible to go the other way. There are a few revolvers in the big .45-70 Gov’t. cartridge. Of course the rifles and the revolvers are relatively massive in comparison to the original idea. If I decided to carry my 1886 and a BFR revolver, along with a large amount of ammo, I would need secondary transportation to handle the weight. The load would probably be double that of a pistol caliber combo.

    2. The reason for this had to do with the case dimensions of the original 45 Colt and its almost nonexistent rim.
      actually … from what i understand … the reason the .45 colt was not chambered in any other firearms … not just rifles … is because it was a proprietary cartridge for the military only.
      that is exactly why the 45 schofeld was created by smith & wesson.

    3. Article is not 100% correct with regard to the m1887 military ball cartridige. It does not have exactly the same case dimensions as the .45 Schofield, because the Schofield case had a rim diameter ever so slightly larger than that of .45 Colt. This apparently caused the rims to interfere with each other when you attempted to use .45 Schofield ammunition in a Colt SAA revolver. You weren’t screwed as badly as an S&W armed trooper who had been issued Colt ammunition, because you could still use the Schofield ammo in your Colt by only loading 3 rounds, so there would be an empty chamber (and therefore no rim interference) between them.

      This problem was solved by standardizing on cases that had the rim diameter of the Colt brass, and the case length of the S&W brass, which was the M1887 Military Ball cartridge that would work in both types of pistol. It’s not one or the other, but its own distinct thing.

      I think that is also the true basis for .45 Colt ammo being known as Long Colt, because at one time there actually was a .45 Short Colt, AKA the M1887 cartridge that was effectively the Colt cartridge trimmed to fit in the shorter S&W cylinder. The people who still refer to it as .45 LC are therefore not necessarily wrong, but still most likely clueless as to exactly why it was called that.

      I learned this after I had the bright idea to try to get another round of magazine capacity out of my M92 lever action by loading Schofield rounds instead of .45 Colt. I bought a box of .45 Schofield for testing, and discovered that it was hanging up in the magazine tube, and it would not feed properly. This led to my doing further research that revealed the above information, that I verified by measuring the rims of both ammunition types. I was a little surprised to find out that the .45 Schofield cases of modern manufacture had been faithfully made to the correct original dimensions and were not merely .shortened .45 Colt brass with a Schofield headstamp.

    4. .45 ACP vs 45 Colt.
      When will this everlasting debate end……
      It is quite simple as to dimentions and for which firearms intented.
      Read books, internet etc, before you insert a .45 ACP into your revolving pistol, without half moon clip that is.
      It is like asking about the difference between a dolphin and a whale whithout consulting readily available information.

    5. I just bought a Taurus the Judge .410/.45LC stamped under the barrel. Took it home to shoot it. Shot the .410 fine. When I chambered the .45 Auto round it went into the cylinder a half inch deep! What type of .45 Cal do I need to have it work in this hand gun? Is there a difference in the seat of a .45 Auto and .45LC? Why does it not seat at the end of the cylinder? Please help with your knowledge.

      1. Obviously your first revolver experience. The .45 ACP has no exposed rim, which as it is with all automatic/semi-automatic clip fed rounds. The rim of the .45 acp is the same diameter as the cartridge casing. You need the .45 colt or .45 “long colt”. These days it is the same round. It has a rim that is larger in diameter than the barrel of the casing. Simply known as .45 colt ‘revolver’ ammo.
        Happy shooting.

        1. OMG…another self proclaimed “firearms expert” who does not know that a clip and a magazine are two different things. A .45 ACP pistol shoots bullets that are loaded and fed through a MAGAZINE, not a clip.
          Even though a magazine and a clip both hold ammunition, a magazine has an internal spring that feeds ammunition. A clip has no internal spring.
          God Help us…..

    6. Great picture of the Ruger Vaquero birdshead model. I like how the picture caption says “Old Vaquero”. In an article about correct nomenclature, we probably shouldn’t be calling it an Old Vaquero, since there was never a model called “Old Vaquero”. Takeaway for me is that I own an Old Vaquero in 45 Long Colt. Fun article though.

        1. .45 colt .45 acp
          Again: a few revolver constructions were chambered for the .45 acp, headspacing/chambering on the very slight edge of the shell mouth. Not very successfull, misfires due to lack of longitudenal support of the cartridge.

    7. Is there a 1911? That was ever chambered for the 45. Colt. I’ve just recently started learning about this ammunition cause I bought a Bond Arms Snake Slayer IV. Love the POWER the 45. LC produces and Federal has got a great low-recoil round also( a smaller grain bullet ) I favor the 250+grain rounds though…

    8. It’s interesting to read why some people still refer to 45 Colt as “45 Long Colt”. No ammo manufacturer that I know of sells what they call “45 Long Colt’. When I think of 45 caliber handgun ammo, I think of 45 ACP or 45 Colt.

    9. You’d be well on your way to sounding halfway intelligent if you actually admitted that SCCY has been lying about releasing the CPX-3 for the last two years. Sorry for the contraction, little Mikey.

      1. No because of the larger rim BUT, you can build or buy an AR in 450 Bushmaster. It’s basically a 45 ACP stretched to fill an AR magazine pushing the same jacketed bullet at over twice the velocity. The perfect deer rifle …….

    10. Why was there a debate on this to begin with? I’ve always heard this ammunition referred to as both .45 Colt and .45 Long Colt. I’ve even done so myself. I just figured that saying “.45 Colt” was just the abbreviated version.


      1. I owned one and used it in Cowboy Action shooting. I loaded it with 38 Special hand loads, however, it may have chambered 357 Magnum. The revolver had a 5 inch barrel. I noticed the guns made to chambered in 45 Colt were more readily available and less costly.

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