Until around 1840, the flintlock priming system was most commonly used. The hammer that held a piece of flint with a clamp dropped down, making the flint strike the metal frizzen. The spark that one sees was actually a bit of the metal frizzen that was chipped off. That spark fell, still hot, into the a pan containing priming powder. That then set off the priming powder which, in turn, ignited the main charge.
After around 1840, Scottish clergyman Alexander Forsyth invented fulminate priming. That invention was advanced by men, such as Joshua Shaw, who enclosed fulminates in copper.1 The percussion system, which included the fulminate priming system, greatly simplified the ignition process. In the percussion system, a plain metal hammer struck a priming piece—either a cap, disk, or tape containing fulminate—that was over a metal cone, more commonly known as a nipple. The nipple had a hole in it and attached to a tube called the fire communication, which carried the spark from the hammer and primer down to the chamber where the ball and powder was located, causing an explosion and firing the gun.
With the invention of the percussion system, inventors began creating and improving priming methods. One of the priming systems used in the first part of the Civil War was the Maynard Primer. Dentist Edward Maynard patented his percussion-primer on September 22, 1845, and the patent was numbered 4,208. He invented a priming tape that had separated circles of priming material containing fulminate. That tape was wound around a feeding wheel that turned on a pin in the raindrop-shaped magazine, which was attached to the gun’s lockplate. A spring hoop fitted inside the bottom part of the magazine surrounded the wheel containing the coiled tape. According to Maynard’s patent “that spring hoop receives the movement which it transmits to the feeding wheel from the cock or hammer by a projection,” a small piece of the breech mechanism. Then, the spring moved the feeding wheel a rotation of one cog, feeding the tape up through a channel and then through the magazine’s top. One primer circle then lined up directly with the hammer and the nipple. One side of the hammer’s bottom had a knife-edge. As the hammer fell down, the tape was cut, and the primer was carried down to the nipple.
Sharp's Pellet Primer
Christian Sharps created another priming method, called the Sharps Pellet Primer. That pellet primer was patented on October 5, 1852 and numbered 9,308. The priming system used small disks that contained fulminate called pellets. A tube that held the priming pellets was built into the lockplate. The tube had a piston attached to a helical spring, which rested on the screw that closed the bottom of the tube. As less and less pellets remained in the tube, the spring pushed the piston up so that the pellets always remained at the top of the tube. There was a metal arm attached to the driver that pushed or threw the pellets. That arm fit into the right-angle groove in the side of the hammer. When the hammer was fully raised, the driver was in its farthest back position. The spring and piston raised one pellet. When the hammer fell, it pushed the driver forward. The driver struck the pellet, throwing the primer between the closing hammer and the nipple right as the hammer came down to hit the nipple. The Sharps Primer was one of the most technical systems and required great manufacturing precision. Similar to the Maynard Primer, the mechanism allowed for less reloading time between shots, because the soldiers did not have to constantly reload their primers.
The most common type of primer was known as the percussion cap. The cap was made out of copper that was shaped like a top hat. On the top of the cap, manufacturers placed a small amount of mercury fulminate. Before each shot, the marksman cocked the hammer, and put the cap on the nipple. Percussion caps were more reliable when firing than flintlocks and more resilient to the weather.2
The cap was more reliable than that of the Maynard Priming System, whose tape was not water resistant. Richard Lawrence’s “shut off” invention that blocked the Sharps Pellet Primer’s magazine whenever the marksmen chose demonstrated that the Sharps also used percussion caps (Lawrence even specified that as a reason for his patent). The switch to percussion caps may have been due to the Ordnance Department’s effort to standardize arms as much as possible to simplify procurement.
The last priming system advancement used in the Civil War was located on the bottom of the metal cartridge. The hammer struck one or two pins that then hit the rim of the cartridge directly, setting off an explosion to fire the gun. Rimfire cartridges made repeating arms possible. Those rimfire cartridges were the precursor to centerfire, where a pin would strike the center of the metal cartridge’s bottom.
1 Joseph G. Bilby, A Revolution in Arms: A History of the First Repeating Rifles (Yardley, Pennsylvania: Westholme Publishing, LLC, 2006), 34.
2 Roger Pauly, Firearms: The Life Story of a Technology (Baltimore: The John Hopkins University Press, 2004), 83.
Priming Systems: From Flintlock to Percussion Rimfire