Oh my goodness.
Entire books have been written just about the Single Acton Army, and you want to know everything there is to know about them in a post on a web forum?
Let's start with the Colt Army Special, less to bite off.
Introduced in 1908 and manufactured until 1927. Originally chambered for 32-20, 38 Colt, 38 Smith and Wesson and 41 Colt. This one shipped in 1921 and it is chambered for 38 Special. This one shipped with hard rubber grips.
Built on a frame slightly larger than a K frame Smith and Wesson 38 Special. All the revolvers in this photo are chambered for 38 Special. Left to right they are a Colt Police Positive Special, the Colt Army Special, a S&W K-38 and a S&W Model 14-3.
The truth is I have not put a whole lot of rounds through this Army Special. However it has the same 'V' shaped hammer spring as most other Colt double action revolvers. More difficult to find a smith who is used to working on them than a S&W revolver. Colts like this are often said to go out of time more easily than S&W revolvers, I have no direct experience with that either.
By 1927 Colt decided to stop pursuing military contracts for this revolver and to concentrate on law enforcement agencies instead. At that time the name of this model was changed to Official Police. It is the same revolver, just a different name. The Official Police was produced up to 1969. Originally chambered for 32-20 as well as 41 Colt, those chamberings were dropped in 1942 and 1930, respectively. Chambered for 38 Special through out the production run, 22 Rimfire was added in 1930. Total production of the Official Police was about 425,000 units.
The Colt Single Action Army is the iconic Cowboy revolver. Although many different revolvers were produced during the period of the Old West, the SAA is the most ubiquitous.
Colt had been producing Percussion (Cap & Ball) revolvers since 1837 with the Paterson Colt. It would take an entire book to document all the C&B revolver models produced by Colt, but off the top of my head a few are the Paterson, the gigantic Walker Colt, the Dragoon series, the 1851 36 caliber Navy and the 1860 44 caliber Army. Probably a few others I am not coming up with right now.
In 1855 Smith and Wesson obtained control of the Rollin White patent. Rollin White was a Colt employee. At a time when all revolvers were C&B, meaning they had to be loaded by pouring loose powder into the chambers, then ramming a ball on top, and finally capping the nipples at the rear of each chamber with a percussion cap, White came up with the novel idea of boring the chambers completely through the cylinder, so a cartridge could be inserted into the rear of the chambers. Metallic cartridge manufacturing was in its infancy at this time, and loading a revolver with cartridges for much quicker reloads was a revolutionary idea. White made up some crude demonstration models of his idea and presented them to Colt, and in what must have been the worst business decision of his life, Colt passed on the idea. So White obtained a government issued patent on the idea himself in 1854. A year later S&W came knocking at White's door. Daniel Wesson and Horace Smith had formed a new company. Wesson had designed a tiny 22 caliber revolver with a bored through cylinder to accept a tiny 22 caliber cartridge we would call the 22 Short today. In his research into the project Smith discovered White had already patented his idea for a bored through chamber. A deal was struck where White gave S&W exclusive rights to manufacture revolvers using his patented idea of a bored through cylinder and S&W paid White a royalty of $.25 for every revolver they manufactured. The story gets more interesting, but suffice it to say that all through the Civil War Colt, Remington and all the other revolver manufacturers were not legally able to produce a cartridge revolver, the Civil War was fought mostly with obsolete C&B revolvers. During this time S&W was producing 22 and 32 Rimfire cartridge revolvers. S&W did not have any government contracts at this time, but many soldiers bought the largest revolver S&W was making at that time, the #2 Old Army. This was a six shot Tip Up style revolver that fired a 32 Rimfire cartridge. Although it was much faster to reload than a C&B revolver, the 32 Caliber Tip Ups were not as powerful as the big 44 C&B revolvers that Colt, Remington, et al were producing at the time. S&W experimented with a 44 caliber Tip Up, but the mechanism was not strong enough, so no Tip Ups were ever manufactured larger than 32 calbier.
This is a S&W #2 Old Army pictured with six rounds of 32 Rimfire ammunition. It left the factory in 1863.
White's patent did not expire until 1869, four years after the Civil War ended. At that time S&W was sure all the other revolver manufacturers would have cartridge revolvers designed and ready to sell, so they came up with a revolutionary new design known as a Top Break. The selling point of the Top Breaks was not only did they accept metallic cartridges, but the barrel and cylinder rotated down to reload and empty brass was automatically ejected as the barrel swung down. Besides being not very strong, in order to reload a Tip Up one undid a latch at the bottom of the barrel, rotated the barrel up, removed the cylinder and poked the empties out with the rod at the bottom of the barrel.
Like this. The process was reversed to reload.
This is a S&W New Model Number Three from a little bit later, but it illustrates how the barrel and cylinder rotated down and the empties were automatically ejected on a Top Break. In this photo the barrel and cylninder have been rotated about halfway and the ejector is starting to rise and eject the empties.
Colt had not been asleep during the time that led up to the White patent expiring in 1869. They came up with several 'Conversion Models' that were able to use the idea of loading a cylinder with cartridges from the year. The first was the Thuer Conversion that used an odd cartridge with a reverse taper in an attempt to get around the White patent. It was not a commercial success. Later they came up with the Richards Conversion, the Richards-Mason Conversion, and finally the Open Top. The first two used parts of from C&B inventory. Some had the cylinders cut down to accept cartridges, some had new cylinders made. The Open Top was actually designed from the ground up as a cartridge revolver, but it is usually lumped in with the Cartridge Conversions.
This is a Richards Conversion pictured with a few of the 44 Colt rounds it was chambered for. As can be seen, the C&B loading lever is gone replaced by an ejection rod screwed to the side of the barrel.
The rear of the cylinder of the Richards Conversion was cut back, cutting away the area where the nipples had been, and a Breech Plate was fastened to the frame to take up the space. A loading gate was attached to the Breech Plate so cartridges could be loaded and unloaded by rotating them past the loading gate, just like on the later Single Action Army.
This photo shows the Breech Plate with the loading gate open.
The Richards Conversion also featured a revolutionary concept, a frame mounted firing pin.
The Richards-Mason Conversion made improvements to the earlier Richards Conversion by making some of the parts less complicated and simpler to manufacture.
Remington had not been asleep at the switch at this time, there were a number of cartridge conversions done to Remington C&B revolvers done at this time. Remington even contracted with S&W for the use of the White patent to convert over 4500 revolvers to use conversion cylinders in 1868. There were other conversion revolvers built at this time too.
By 1872 William Mason, of Richards-Mason fame had been working on a 'top strap' revolver to replace the conversion models. The White patent had expired several years earlier, and in 1873 Colt obtained their first contract with the Government to supply the new Single Action Army revolver. Hence the name. It was chambered for the brand new 45 Colt cartridge, which had about 40 grains of Black Powder inside under a 250 grain lead bullet.
Colt Single Action production is generally recognized to comprise three Generations. The First Generation stretched from 1873 until 1940, when production was halted to gear up for WWII. The 1st Gens were chambered for no less than 30 cartridges. No, I am not going to list them all. After the War ended Colt had no plans to reintroduce the SAA. They felt there would be no interest in such an old fashioned revolver. But thousands of GIs returning home took advantage of the GI Bill to go to college and buy homes. And many of those homes had brand new television sets with cowboys riding through living rooms all over the country. This generated new interest in the old 'cowboy gun'. In 1953 an enterprising young man named Bill Ruger produced a small 22 rimfire single action revolver and they sold like hot cakes. In 1955 he made a bigger one chambered for 357 Magnum. Colt finally saw the writing on the wall and reintroduced the SAA in 1956. This was the 2nd Gen and it was produced until 1975. At that time some design changes were made and the 3rd Gen was introduced and that has been made ever since.
Standard 2nd Gen chamberings were restricted to 45 Colt, 44 Special, 357 Magnum and 38 Special. Currently the Colt website is only listing 45 Colt as a chambering for the 3rd Gen, but I'm pretty sure a few other chamberings were available at one time.
Standard information about all generations of the Single Action Army:
No, they are not compatible with 45 Colt +P ammunition. First off, there is no official SAAMI standard for 45 Colt +P ammunition, it is what ever each manufacturer thinks is appropriate.
45 Colt SAA revolvers should only be fired with SAAMI max 45 Colt ammo that develops no more than 14,000psi. Yes, this is open to debate, but you will not find me shooting any of that more powerful stuff in my Colts.
This is the rear of a 45 Colt 2nd Gen cylinder. Notice how thin the webs of steel are between each chamber. More significant, but not visible in this photo is how thin the metal is between the 'top' of each chamber and the bottom of the bolt stop cuts. Only a few thousandths in most cases. That is why '+P 45 Colt ammunition' should never be fired in a SAA chambered for 45 Colt.
Yes, 357 Magnum SAA revolvers can be safely fired with standard SAAMI Max 357 Magnum Ammunition. The cylinder is just as large, but the holes are much smaller. The SAA was first chambered for 357 Magnum shortly after S&W developed the cartridge in 1935. They were safe to shoot then and the steel is stronger now so they are still safe to shoot with factory 357 Magnum ammo.
A 44 Special SAA will not chamber a 44 Magnum round. Obviously 44 Special pressures should be kept to standard 44 Special levels.
While I am talking about ammunition, Colt did not factory warranty the SAA for Smokeless ammunition until 1900, part way through 1st Gen production. Up to that time Colt did not feel the steel they were using (actually iron in the very early frames and cylinders) was strong enough for the pressures of Smokeless ammunition. By 1900 they felt confident their metallurgy had progressed enough for the pressure of Smokeless ammunition. A year or two later they began stamping 'VP' inside an upside down triangle on the front left of the trigger guard. This stands for Verified Proof, and it means the firearm has been proofed for Smokeless ammunition. Colt revolvers manufactured before 1900 should not be fired with modern Smokeless ammunition, although this gets argued all the time. This is a Bisley Colt that left the factory in 1909, so it is safe to fire with Smokeless ammunition. I never do, I only fire it with ammunition loaded with Black Powder.
Let's look inside a SAA for a moment. The part between the hammer and the frame is the hand. Notice the spring attached to it. Notice too the spring with two legs between the frame and the trigger. That is the bolt/trigger spring. It operates the bolt, which is the part just in front of the trigger, and the trigger. (the bolt is the part that pops up out of the frame to lock the cylinder in position for firing)
For many years, shooters familiar with the Colt SAA have known they are not safe to carry fully loaded with six rounds and the hammer down on an empty chamber.
These are the lock parts of a SAA. The upper arrow is pointing to the so called 'safety cock' notch on the hammer. The lower arrow is pointing to the tip of the trigger called the sear. The sear fits into each of the cocking notches on the hammer when the hammer is cocked back different amounts. Notice how thin the sear is. When the hammer is brought back to the 'safety cock' position the firing pin is pulled back from the primer of a cartridge under the hammer. But if a strong force is applied to the hammer spur, such as dropping the gun on its hammer, there is an excellent chance the tip of the sear will break off, or the overhanging lip of the cocking notch will break off. If that should happen there is an excellent chance the firing pin will strike a cartridge under the hammer with enough force to fire the cartridge. This has been documented many times. So it is only safe to carry a SAA with five rounds in the cylinder, with an empty chamber under the hammer. If you want to safely load six, buy a Ruger. All modern Rugers come with a transfer bar inside that makes them completely safe to carry fully loaded with six rounds.
This is the way the split bolt/trigger spring sits in the frame. One leg pushes the bolt up, the other leg pushes the trigger back.
The bolt/trigger spring is the part most subject to failure in a Colt. Over time as it flexes over and over again stress risers can be created and it can fail. Just like this. Don't get me wrong, the spring is not going to break the first time you shoot the gun. I have Colts that are over 100 years old with their original springs. But this spring can break. There are modern springs made of music wire that can easily be substituted for this spring. I forget right now, but I'm pretty sure at least one of my Colts has a wire bolt/trigger spring inside.
The hand spring is also fairly subject to breaking. Right at the curve where it is peened into the hand. Again, not guaranteed to break, most of my Colts have their original hand springs inside. But they can break. Most modern replicas of the SAA come with a coil spring that operates the hand, very similar to a Ruger. Those springs never break.
Uberti has recently changed the design of their replicas of the SAA to include a retractable firing pin in the hammer. The jury is still out on this, but the idea is to make them safe to carry fully loaded.
I see somebody has already commented on how difficult to maintain the SAA is. It is not. Just keep it clean, check to see the screws are tight, they tend to loosen from firing, and be aware the bolt/trigger spring or the hand spring may fail at some point. Colts are so simple to take apart I can almost do it blind folded. Almost, not quite.
For your viewing pleasure, a few Colts.
This pair of 2nd Gens are my usual Main Match pistols in Cowboy Action shooting. The one at the top left the factory in 1973, the one at the bottom in 1968. Both are chambered for 45 Colt but I only shoot them with ammunition loaded with Black Powder.
Another pair of 2nd Gens chambered for 45 Colt. Unlike the pair above that I have been shooting for many years, this pair is in almost like new condition. The one at the top of the photo shipped in 1973, the one at the bottom in 1963.
A 1st Gen Bisley that shipped in 1909. Chambered for 38-40. Almost no blue left from over 100 years. This is the one in the photo above of the VP on the trigger guard. Yes, the ejector rod handle is bent and I am leaving it just like that so I don't break it off trying to straighten it.
Another 1st Gen 38-40 Bisley that shipped in 1907. The colors of the Case Hardened frame and the blue are still quite strong on this one.