Invented around 1828 by Casimir Lefaucheux
, the pinfire cartridge
was the first enclosed
round. Prior to the development of the pinfire cartridge, a weapon
had to be loaded with powder, ball, and igniter (over the years, the source of ignition changed as technology progressed from matchlock
to percussion cap
.) The pinfire round enabled a weapon to be rapidly reloaded faster than any method previously.
There were unfortunately two drawbacks to the design, one more significant than the other. The first was that due to the bullet's shape, it could not easily be used in a repeating rifle. The cartridge had a little pin that stuck out on one side. This pin went into the round and sat in a percussion cap inside the case, so when it was struck by a hammer, the round would go off. This meant that only revolving bullet carriers could be used, as they allowed the pins to stick out. As a result, only pistols were made using the round. (Chase points out that there were single-shot pinfire rifles. They would be much, much better than a muzzle-loader, but would still suffer from single-shot action.)
This lead to the second, more dangerous, problem. A blow with any force behind it would cause a round to go off. That meant a soldier with a bandolier of bullets was at constant risk of blowing his hip (or worse) off. The rimfire bullet was a welcome replacement.
They were quite popular during the Civil War, however, as the more modern rimfire bullet was only then being fielded, and because of its utility in rifles, military priority was given to those designs, such as the Spencer Rifle and Henry Repeater. (An army wins or loses on the line soldier's weapons. It has been often said the M1 Garand won WWII.) Many officers and gentlemen continued to use the pinfore revolver for another 15 years or so, as it was a perfectly functional personal weapon. Many smaller versions did not have trigger guards, instead using hinged triggers to slim the pistol for stowing in a pocket.
Another interesting idiocyncracy of many pinfire revolvers is that a popular Belgian design smuggled to the Confederates (they have makers marks but no serial numbers) fired double-action from a down hammer using a novel trigger cocking mechanism that allows the pistol to get off the first shot quickly. (I would imagine a gentleman gambler appreciating that.)
On a personal note, I own an antique pinfire revolver. It was probably owned by an officer and/or dandy, as it has beautiful flowery scrollwork. (Once upon a time it was ok to love beauty and still be a tough guy.)
It was modified shortly after it was made (it had to have been a short time after its manufacture as it had a very short window of utility, due to its being superceded by rimfire designs.) The firing mechanism was altered from single-action to one-off double-action. (I have since found that this novel action is particular to this maker's work, and have also addressed this in the writeup above.) I say one-off because in order to fire again, the weapon had to be cocked in a special fashion using the trigger, not the hammer.
(If any of you reading this are gunsmiths and/or historians and think this makes it extremely rare and valuable, email me!!!)