50 Shades of .45

45 Caliber history: 50 shades of 45
February 11, 2020  
Categories: Learnin'

From our earliest cartridge firearms to the biggest hunting and defensive rounds used today, the 45 caliber is one of those ideal bore diameters for hurling lead downrange.

I am sure there are a few more of these out there, especially in rare wildcats or obsolete rimfires, pinfires, and even obscure centerfire rounds, but there are at least 50 shades of 45 ammo that have spanned the past 200 years.

Understanding .45 Caliber


As a firearm super-user and a 45 caliber fan, I was surprised to only have firearms capable of shooting a dozen of these calibers. I definitely need to up my game!

How many are on your ammo checklist?

50 shades of 45

1. 450 Adams or 450 Boxer Mk I

450 Adams - a historic 45 caliber.

One of the first 45 caliber rounds was the 450 Adams. It originated in 1868 for the British military in the converted Beaumont–Adams revolver and saw service for 12 years. An early black powder round, it had a short case, was loaded with a 226-grain bullet, and it traveled at 650-700 FPS.

2. 450 Revolver or 450 Colt or 450 Short or 450 Corto

A variant of the 450 Adams, 450 Revolver these were generic names for the same load in a similar case by manufacturers (Colt, S&W, and Webley) who did not want to advertise John Adams’ revolvers. It is believed General Custer carried a brace of Webley RIC revolvers chambered in the 450 Short cartridge at the Battle of the Little Big Horn.

3. 11mm French Ordnance

11mm French Ordinance - 45 caliber

Image source: mdshooters.com

Even though they use a metric name (because they never went to the moon) this is a rimmed black powder cartridge in 45 caliber intended for the 11 mm MAS 1873-1874 revolver in service with the French Army. The velocity and power of the first variant is the equivalent to the 25 ACP despite the large bullet and it was weak even for its time.

4. 11mm Pinfire

11mm pinfire - 45 caliber round.

Image source: svartkrutt.net

Another metric wonder, the 11mm Pinfire was developed by Casimir Lefaucheux of Paris, France in the early 19th century. Many of these revolvers made their way to the US and pop up from time to time as antiques. The ammunition became obsolete once the science of rimfire and centerfire cartridges came of age in the last decade of the 19th century.


5. 450 Black Powder Express

The .450 3¼-inch Black Powder Express cartridge was originally designed as an experimental military cartridge for the 1869 British Army Rifle trials that lead to the adoption of the Henry-Martini rifle. Image source: Gun Wiki.

.450 3¼-inch Black Powder Express cartridge. Image source: Gun Wiki. .450 3¼-inch “long chamber” cartridge

This 45 caliber round was originally developed as an experimental military cartridge for the 1869 British Army rifle trials that led to the adoption of the Martini-Henry rifle. The original military cartridge was loaded with a bullet weighing 480 grains. When lighter projectiles were introduced at higher velocities the 450 Black Powder Express became the most popular sporting Express cartridge throughout the world and well into the 20th century.


6. 45 Colt

When Colt’s Single Action Army Revolver of 1873 debuted in that same year, the 45 Colt round went along with it for the ride. It saw service for 20 years, but never really went away. Shooters simply loved the round. A very versatile cartridge, it can be loaded to levels that exceed the 44 Magnum, but only in modern firearms capable of handling the pressure.


7. 45-70 Government

45-70 Government - 45 caliber.

Image Source: Steinel Ammunition.


Officially referred to as the 45-70-405, this round from 1873 obtained its name from its use of a 45 caliber bullet, 70 grains of black powder and a 405-grain lead bullet. As the round moved into the civilian sector the last part of the name was dropped as different sized bullets were used and were often known simply as “45 Government” or “45 Springfield”. It was also used in the single-shot Sharps rifle of the era. Still in use today, the 45-70 became a very popular hunting round throughout North America. So popular, it decimated the Bison herd throughout the United States in the 19th century.


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8. 45-75 Winchester

45-75 Winchester

Image Source: Guns International.

This round made its debut with the Winchester Model 1876 lever-action rifle. This was an enlarged version of the famous Model 1873 action designed for use with cartridges up to 2.25″ in length. Shorter and fatter than the 45-70 Government. It was never developed to its full potential due to the weakness of the action of the Winchester 1876.

9. 45-60 Winchester

45-60 Winchester - 45 caliber

Image Source: Liberty Tree Collectors.

Winchester Repeating Arms Company shortened the 45-70 government cartridge to operate through the Winchester Model 1876 rifle’s lever-action. The Colt Lightning Carbine and the Whitney Arms Company’s Kennedy lever-action rifle were also chambered for this round. It became obsolete by 1886 and the introduction of the Winchester Model 1886, capable of chambering the more common and affordable 45-70.

10. 45-90 Sharps

45-90 Sharps - 45 caliber


A few years after the introduction of 45-70, the 45-90 Sharps was introduced. It was slightly longer, took 20 more grains of black powder and was developed for hunting and long-range target shooting with the Sharps rifle.

11. 45-120 Sharps

45-120 Sharps - 45 caliber

Image source: Buffalo Arms.

Introduced in 1879, the 45-120 Sharps was developed as a long-range and powerful bison cartridge. The rimmed, straight taper case was 3.25″ long with a head diameter of .506″ and neck diameter of .490″. The overall length was 4.16″ with a bullet loaded.

12. 45-90 Express

This round is a modern adaptation of 45-90 Sharps which uses the same 2.4″ case, but smokeless powder loads take the pressures up to 45,000 psi. With a 26″ barrel the 45-90 Express is capable of over 4,200 ft-lbs of muzzle energy.

13. 45 Schofield

45 Schofield - 45 Caliber

In 1875, the US Military wanted a top-break single-action revolver and Smith & Wesson modified its Model 3 top-break to the Army’s specs. After initial delivery, they found the issued 45 Colt ammunition to be too long and with too small of a rim. S&W responded by shortening the case and thickening the rim to improve extraction. Although the 45 Schofield will chamber in a handgun intended for the longer 45 Colt, the reverse is not the same which created logistical problems in the field. This led to the nickname of “45 Long Colt” for the ammunition called 45 Colt.

14. 475 Eley/476 Enfield

475 Eley / 476 Enfield - 45 caliber

As cartridge firearms took hold and were improved upon, the 450 Adams got a makeover in 1880 as the 475 Eley/476 Enfield. 18 grains of black powder and a 265-grain slug made it a bit more potent than its predecessor.

15. 45 Webley

45 Web

Another variant of the Adams was the 45 Webley intended for use in the Bulldog and RIC revolvers. It was somewhat rare and feeble with a 230-grain bullet in the 550-650 fps range.

16. 455 Webley Mk ll

455 Webley Mk ll

Adopted in 1897 and was used until the 1940s, this was a heavy 265-grain bullet that went down range at 600-700 fps. Several variants of this ammunition were made over the years and Fiocchi still makes this ammunition in small batches.

17. 450 Nitro Express

John Rigby developed this as the first Nitro Express cartridge in 1898 as a dangerous game round for use in his double rifles. Muzzle velocity is typically 2,150 fps with 4,909 ft-lbs of muzzle energy. This straight-wall case is 3.25″ in length.

18. 450 No 2 Nitro Express

450 Nitro Express - 45 caliber

The 450 No 2 Nitro Express has a massive 3.5″ long cartridge case which has a large case capacity and compared to other similar Nitro Express cartridges has a thicker rim and heavier walls. The size of the cartridge case gives it some of the lowest chamber pressures amongst the Nitro Express cartridges. It was designed in 1903.

19. 455 Eley

A slightly longer 455 Webley, this round was made famous by the RCMP and was chambered in the Colt New Service Revolver.

20. 45 Remington–Thompson

45 Remington–Thompson - 45 caliber

This was an experimental firearms cartridge designed by Remington Arms and Auto-Ordnance for the Model 1923 Thompson submachine gun. It was a variant of the Model 1921 with a longer barrel, with the intent of increasing the power and range of the weapon. While some variants of the 1923 were produced, the SMG and round did not find commercial success.

21. 45 Peters-Thompson shot cartridge

45 Peters-Thompson shot cartridge

Developed in 1923 for the Thompson submachine gun, this 45 caliber ammunition consists of a waxed paper bullet containing about 150 No. 8 chilled shot propelled by what appears to be Ballistite shotgun powder. A perforated tin cup separates the paper-covered shot charge from the powder and maintains the alignment in the bore until it leaves the muzzle. It was developed for police use in riots where it is not desired to seriously injure offenders.

22. 45 Automatic Riot

45 Automatic Riot - 45 caliber

Another police load developed for the Thompson, this round consisted of a hollow short copper jacket containing a round lead ball; a 45 caliber lead disc about 1/16th of an inch thick with a flat-topped hump in the center to fit into the jacket base and two flat lead discs.

23. 455 Webley Automatic

455 Webley Automatic - 45 caliber

This was another obscure and rather anemic British round developed in 1912 for a Webley semiautomatic pistol. The round and the pistol were scrapped by the end of World War 1

24. 45 Auto Rim

45 Auto Rim

Due to shortages of 1911 pistols in World War 1, the US Military adopted the 1917 pattern revolver based on the Colt New Service in 45 ACP. M1917s were made by both Colt and their rival Smith & Wesson. Because of problems with the full moon and half-moon clips used to seat rimless auto pistol cartridges in the cylinder, the 45-auto rim was developed in 1920.

25. 458 Winchester Magnum

458 Winchester Magnum - 45 caliber

Image source: American Shooting Journal.

In the 1950s, Winchester wanted to develop a big game cartridge for use in a bolt-action rifle that could compete with the big bore double rifles produced in England for big game in Africa. This belted Magnum, straight-taper cased was introduced commercially in 1956 in the Winchester Model 70 African rifle. The performance of this round was met with mixed reactions and proved to be inferior against dangerous game, however.

26. 460 Weatherby Magnum

460 Weatherby Magnum

Image source: SWFA Outdoors.

This is a belted, bottlenecked 45 caliber rifle cartridge, developed by Roy Weatherby in 1957. It is based on the 378 Weatherby Magnum necked up to accept a .458″ bullet for use as an African dangerous game rifle cartridge for the hunting of heavy, thick-skinned game. It was the world’s most powerful commercially available sporting cartridge for 29 years until the advent of the .700 Nitro Express.

27. 458×2-inch American

458×2-inch American

Image source: gunauction.com.

This short-lived hunting round was designed as a medium power big-bore cartridge by Frank Barnes for North American big game. Barnes found the 458 Winchester Magnum too powerful for North American big game and believed that a cartridge of lesser power would be ample for the task.

28. 460 A-Square Short

460 A-Square Short - 45 caliber

This was a proprietary 45 caliber cartridge designed by Art Alphin of A-Square Rifles. Based on a shortened 460 Weatherby Magnum case, the round can be fired in a standard length rifle action and is capable of developing 6,670 ft-lbs when firing a 500-grain bullet at 2,450 fps.

29. 458 Lott

458 Lott - 45 caliber

Image source: Africa Hunting.

Jack Lott, a big-game hunter and writer for Guns & Ammo, had been hunting with the then-new 458 Winchester Magnum in 1959. When his rifle failed to stop a cape Buffalo and Lott was injured, he felt he needed a more powerful version of that round for hunting dangerous game in Africa. Fourteen years later, the round that bears his name was produced and was chambered in rifles built by A-Square Rifle Company.

30. 450 Ackley Magnum

450 Ackley Magnum- 45 caliber.

Image source: GunBroker.com.

The 450 Ackley Magnum was designed in 1960 by Parker Otto Ackley and is comparable to 458 Lott. Case capacity and performance slightly exceed the 458 Lott. Typical loadings involve a 465-grain bullet at 2,400 fps.

31. 450 Watts Magnum

Designed by Watts and Anderson, the 450 Watts Magnum is another contemporary of 458 Lott with a longer case length (2.85″). A 450 Watts Magnum chamber will accept the 458 Lott cartridge without issue as well as the 458 Winchester Magnum. can be fired in the chamber if required. The 45 caliber round can be fired in rifles chambered for 450 Ackley Magnum, 450 Barnes Supreme and 450 Mashburn Magnum with a reduction in performance.

32. 45 Winchester Magnum

45 Winchester Magnum - 45 Caliber.

Image Source: Buffalo Bore.

In 1979 the dimensions of the 45 ACP case were lengthened for use in the Wildey auto pistol and later the Thompson Center family of single-shot pistols. LAR manufactured an oversized 1911 for use with this one, too.

33. 454 Casull

454 Casull - 45 caliber

Handgun and ammunition pioneer Dick Casull came out with this 45 caliber powerhouse that bears his name in 1957 for use in revolvers made by Freedom Arms. Many years later firearms companies like Taurus and Ruger would build revolvers in the same caliber. It is a lengthened and strengthened 45 Colt case and has been used to take nearly every species of game on the planet from jackrabbits to elephants.

34. 451 Detonics Magnum

451 Detonics Magnum - 45 Caliber.

Image Source: gunauction.com.

This is a pistol cartridge similar to 45 ACP with a reinforced case to handle higher pressure loads. The parent case is the 45 Winchester Magnum trimmed down to 23.9mm in length. It was deliberately made 0.9mm longer than the 45 ACP cartridge to avoid accidental chambering in weaker guns.

35. 45 Super

45 Super

In 1988, a Gun World article detailed Editor Dean Grennell’s efforts to update the 45 ACP for the 21st Century, a difficult endeavor due to the inherent design limitations of the veteran round. A 451 Detonics round was trimmed to the case length of the 45 ACP. The round can be fired through H&K pistols chambered in 45 ACP as well as third-generation S&W semi-autos with updated springs.

36. 450 SMC

450 SMC

The 450 SMC is a variant of the 45 Super which uses a smaller primer pocket to support higher pressure, and therefore velocity because the case is stronger due to having more brass in the web area.

37. 450 GNR

450 GNR - 45 caliber

Image Source: Reeder Custom Guns

A Wildcat cartridge developed by Gary Reeder for use in a Thompson Center Encore. The parent case is a 348 Winchester shortened and expanded to .45”. This big bore behemoth throws a 500-grain bullet at 1900 fps.

38. 455 GNR

Another Wildcat cartridge developed by Gary Reeder for use in a Thompson Center Encore and in some custom revolvers. The parent case is a 475 Linebaugh bottlenecked to .45”. It is said to have more power than a 454 Casull with less recoil.

39. 457 GNR

457 GNR - 45 caliber

Image Source: Reeder Custom Guns.

Gary Reeder does not stop when it comes to making new rounds that seem to push the limits but are very safe. This one is based on the 45-70 or 475 Maximum case.

40. 460 Rowland

460 Rowland - 45 caliber

Image Source: Clark Custom Guns.

Designed by country singer and shooting show host Johnny Rowland, this round is 1.4 mm longer than a 45 ACP case to prevent it from being chambered in standard 45 ACP firearms. The 460 Rowland provides approximately 40% greater velocity than the .45 ACP +P.

41. 450 Rigby

450 Rigby

Paul Roberts, proprietor of John Rigby & Company, was on an elephant hunt in the Zambezi Valley and found his 416 Rigby rifles lacking, as it took several rounds to put the animal down. Once he returned to the United Kingdom he necked up the 416 Rigby case to .458 caliber and the 450 Rigby was born in 1994. This new cartridge fired a .458″ bullet weighing 480 gr at a velocity of 2378 fps.

42. 458 Express

Largely unknown outside of South Africa, the 458 Express was developed in 2000 by Professor Koos Badenhorst of Haenertsburg in the Limpopo province of South Africa. It is essentially a lengthened 458 Winchester Magnum with a case length of 2.99″.

43. 450 Marlin

450 Marlin - 45 caliber

Designed by a joint team of Marlin and Hornady engineers in 2000, the 450 Marlin was developed from the previously mentioned 458×2″ American, which was based on the .458 Winchester Magnum.

44. 457 WWG Magnum

457 WWG Magnum

In 1999, Wild West Guns of Anchorage Alaska developed this round for their Co-pilot Takedown Rifle. Slightly longer then a 45-70 Government, it delivers a 350-grain projectile at 2,200 fps. It is made by shortening a 45-90 case.


45 ACP

45 ACP

Image Source: Alquist Arms

It might mark you as a “Boomer” if you still use this round, but it makes a great “Boom” when fired, so the title is apt! Until recently it was considered the “King of the Auto Pistol rounds” and has seen service in the US Military from its debut in 1911 to the present day.

Chambered in the 1911 pistol, the single-shot Liberator pistol, the Thompson submachine gun, M3 Grease gun, Mk 23 SOCOM Pistol and the ubiquitous Uzi. It is a long-time American favorite 45 caliber of every generation.

46. 460 S&W

460 S&W - 45 caliber

Image Source: Steinel Ammunition

Not to go undefeated, Smith & Wesson made the 454 Casull case longer and christened it the 460 S&W. Chambered in a 460 S&W revolver, this sounded the death knell for single shot and bolt action hunting pistols chambered in rifle calibers such as 308 Winchester and 30-06 Springfield. Surprisingly, the recoil is relatively mild, due mostly to the size of the revolver.

47. 458 SOCOM


Image Source: Steinel Ammunition,

Marty ter Weeme of Teppo Jutsu designed this cartridge in 2000 and Tony Rumore of Tromix was contracted to build the first 458 SOCOM rifle in February 2001. It supposedly came about from informal discussion with members of the special operations command. Very comparable to the 45-70, this rimless cartridge can be chambered in standard AR15 pattern rifles.

48. 45 GAP

45 GAP

Some say this round was a vanity cartridge developed so Glock could have their name on a cartridge headstamp. It is essentially a 45 ACP shortened by 1 mm and was really developed for use in countries where 45 ACP is considered a military round and is unable to be purchased by civilians.

49. 45 Raptor

45 Raptor

Image Source: 45raptor.com

If you wish you could have an AR-rifle chambered in 460 S&W, the 45 Raptor is for you. Announced in April 2014, the 45 Raptor was developed by Arne Brennan of North American Sportsman, LLC. This is a straight wall rifle cartridge that is essentially a rimless 460 S&W Magnum. The rear end of the case is dimensionally the same as a 308 Winchester so it can be used in AR-10 pattern rifles.

50. 450 Bushmaster

450 Bushmaster

Image Source: Midsouth Shooters Supply

Similar in concept to the 458 SOCOM, the 450 Bushmaster is a rifle cartridge developed by Tim LeGendre of LeMag Firearms and licensed to Bushmaster Firearms International. The .450 Bushmaster is designed to be used in the standard M16s and AR-15s, using modified magazines and upper receiver assemblies. Where the 458 SOCOM was developed by lengthening a 50 AE case and necking it down, the 450 Bushmaster was developed by trimming a 284 Winchester case.

And a bonus round for those of you who actually read this all the way through!


51. 45-70 Auto

45-70 Auto

A rimless 45-70 cartridge designed by Aaron Cayce of Phoenix Weaponry, this 45 caliber round delivers the full power of the 45-70 round through a billet upper that is built on the AR-10 platform. This modernized take on the venerable 45-70 generates in excess of 4,000 foot-pounds of energy at the muzzle.


If you enjoyed this article, take a look at other articles that Mike Searson has written for Breach-Bang-Clear.

We also have more articles about ammunition. Check ’em out!

⚠️ Some hyperlinks in this article may contain affiliate links. If you use them to make a purchase, we will receive a small commission at no additional cost to you. It’s just one way to Back the Bang. #backthebang 


Mike Searson

Mike Searson

About the Author

Mike “the Mook” Searson is a veteran writer who began his career in firearms at the Camp Pendleton School for Destructive Boys at age 17. He has worked in the firearms industry his entire life, writing about guns and knives for numerous publications and consulting with the film industry on weapons while at the same time working as gunsmith and ballistician. Though seemingly a surly curmudgeon shy a few chromosomes at first meeting, Searson is actually far less of a dick and at least a little smarter than most of the Mad Duo’s minions. He is rightfully considered to be not just good company, but actually fit for polite company as well (though he has never forgotten his roots as a rifleman trained to kill people and break things, and if you look closely you’ll see his knuckles are still quite scabbed over from dragging the ground). You can learn more about him on his website or follow him on Twitter, @MikeSearson.


  1. Chuck

    If you have a revolver that is .45 acp and you use moon clips or half moon clips, even third moon clips you can fire a .45 gap in such a revolver. Because the .45 acp headspaces on the case mouth, the .45 gap is too short for the 45 acp chamber. It probably will not fire and you may have to use a ramrod in order to remove it from the chamber.

  2. Robert Fields

    That would be like trying to fire a .380 in a 9mm. One principle rule in firearms is to not attempt using cartridges or pressure loadings not specified for that particular firearm. The chamber depth is 1mm deeper (about .040″) in the ACP chambering, so what may, or may not, hold it in battery would be the extractor rather than casing to chamber design, or it would be pushed too far into the chamber to make firing possible. Be prepared for extraction issues, failures to fire, and double feeds. Personally, I wouldn’t do it.

  3. Voldemort

    Is it safe to fire.45gap in a standard .45?


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