Howdy
These are the parts inside a Colt Single Action Army. The upper arrow is pointing to the so called 'safety cock' notch on the hammer. I shoot Colts all the time and I have never heard it called 1/4 cock. The lower arrow is pointing to the tip of the trigger called the sear. Notice how thin the sear is. With the sear in the 'safety cock' notch, it would not take much of a blow to the hammer spur to either shear off the overhanging lip of the 'safety cock' notch, or shear off the tip of the sear. This would allow the firing pin to jump forward and fire a cartridge under the hammer. If the gun were dropped onto a hard surface and landed on the hammer this is pretty much guaranteed to happen.Yes, it has happened many times, in fact dropping a stirrup of a saddle on the hammer spur while preparing to mount a horse could also result in an unexpected discharge, with the bullet hitting the unlucky recipient in the leg. Yes, it has happened. Because the parts are so delicate, it is absolutely unsafe to carry a Colt, or any single action revolver with a similar lockwork, completely loaded with six rounds and the hammer down on a live round. Even with the hammer in the 'safety cock' position.
This is a Colt Single Action Army cylinder loaded with six spent 45 Colt rounds. If one were to place the firing pin between rims, there is very little space. The firing pin would be resting in the narrowest space between rims. I have tried this (with spent rounds like this). The firing pin absolutely will not prevent the cylinder from rotating. The bevel on the edges of the rims allows the rounded tip of the firing firing pin to ride up and over the rims. This technique is not a safe way to carry a Colt chambered for cartridges with large rims, such as 45 Colt, 44-40 or 38-40, which have larger diameter rims than 45 Colt. It might work for 44 Special, I have not tried. It would probably work for 357 Magnum or 38 Special, but I don't have a Colt chambered in those calibers to try.
Yes, the Police Positives had an internal hammer block. The square piece between the hammer and the frame in this Police Positive Special is the internal hammer block. Colt patented this design in 1905, and called it the Positive Lock. This is how the Police Positive series got their name. Once the trigger was released, the hammer block would rise up and wedge the hammer back from the frame.
As either the trigger was pulled, or the hammer cocked, the hammer block would be pulled down. This would allow the hammer to fall all the way to fire a cartridge. As soon as the trigger was released for another shot, the hammer block would rise again, shoving itself between the hammer and the frame.This hammer block was a positive mechanical hammer block. It was moved by the mechanical action of the lockwork. The early Smith and Wesson hammer blocks on the other hand relied on a spring to push the hammer block into the 'safe' position. In my humble opinion, the Colt design was better, as was proven in 1944 when a sailor was killed by a S&W revolver, probably a Victory Model falling to the deck of a warship and discharging. The investigation that followed showed that cosmoline in the mechanism had hardened, preventing the spring from pushing the hammer block into the 'safe' position. S&W changed their hammer block design right after that incident to the current hammer block which is mechanically activated by the lockwork.
The way I heard it, the money in the empty chamber was for the undertaker. Other than Wild Bill, and a few others, not many Colt owners fired their Colts all that much in the Old West. I would suspect that a twenty collar bill rolled up in a chamber would stay fresh and uncharred for a long time.
I took these photos a few years ago when this same question came up in one of the gun forums. Here is a modern twenty dollar bill under the cylinder of a 32 caliber S&W #2 Old Army on the left and a Colt SAA 38-40 on the right.
The twenty does not fit inside the 32 chamber very well.
It fits just fine in the Colt chamber, and this would probably be an excellent place to hide a little bit of money. Who is going to take away your pistol to find your money?
Regarding how many rounds did 19th Century shooters load in their Colts? I'm sure those who actually understood these guns would only load five.
But as John Wayne said once, "If you think you're going to need six, load six."