Loading and Firing Mechanisms

Muzzle-loaded Cannon

The cannon is loaded with gunpowder and the cannonball through the muzzle, while a fuse is placed at the rear. This fuse is lighted, causing the gunpowder to ignite and propel the cannonball. Most cannons were land- or ship-based guns, although hand cannons also existed. In military use, the standard cannon was tremendously powerful, while hand cannon was somewhat useless. In the 19th century, the muzzle-loaded cannon was made obsolete by the breech-loaded artillery piece with a rifled barrel.

Muzzleloader

Muzzle-loading muskets (smooth-bored long guns) were among the first small arms developed. The firearm was loaded through the muzzle with gunpowder, optionally some wadding and then a bullet (usually a solid lead ball, but musketeers could shoot stones when they ran out of bullets). Greatly improved muzzleloaders (usually rifled instead of smooth-bored) are manufactured today and have many enthusiasts, many of whom hunt large and small game with their guns. Muzzleloaders have to be manually reloaded after each shot; a skilled archer could fire multiple arrows faster than most early muskets could be reloaded and fired, although by the mid-18th century, when muzzleloaders became the standard small armament of the military, a well-drilled soldier could fire six rounds in a minute using prepared cartridges in his musket. Before then, effectiveness of muzzleloaders was hindered by both the low reloading speed and, before the firing mechanism was perfected, the very high risk posed by the weapon to the person attempting to fire it. One interesting solution to the reloading problem was the "Roman Candle Gun". This was a muzzleloader in which multiple charges and balls were loaded one on top of the other, with a small hole in each ball to allow the subsequent charge to be ignited after the one ahead of it was ignited. It was neither a very reliable nor popular firearm, but it enabled a form of "automatic" fire long before the advent of the machine gun.

Matchlock

Matchlocks were the first and simplest small arms firing mechanisms developed. Using the matchlock mechanism, the powder in the gun barrel was ignited by a piece of burning cord called a "match". The match was wedged into one end of an S-shaped piece of steel. As the trigger (often actually a lever) was pulled, the match was brought into the open end of a "touch hole" at the base of the gun barrel, which contained a very small quantity of gunpowder, igniting the main charge of gunpowder in the gun barrel. The match usually had to be relit after each firing.

Wheellock

The wheellock action, a successor to the matchlock, predated the flintlock. Despite its many faults, the wheellock was a significant improvement over the matchlock in terms of both convenience and safety, since it eliminated the need to keep a smoldering match in proximity to loose gunpowder. It operated using a small wheel much like that on cigarette lighters which was wound up with a key before use and which, when the trigger was pulled, spun against a flint, creating the shower of sparks that ignited the powder in the touch hole. Supposedly invented by Leonardo da Vinci, the Italian Renaissance man, the wheel lock action was an innovation that was not widely adopted.

Flintlock

The flintlock action was a major innovation in small arms design. The spark used to ignite the gunpowder in the touch hole was supplied by a sharpened piece of flint clamped in the jaws of a "cock" which, when released by the trigger, struck a piece of steel called the "frizzen" to create the necessary sparks. (The spring loaded arm that holds a piece of flint or pyrite is referred to as a cock because of its resemblance to a rooster.) The cock had to be manually reset after each firing, and the flint had to be replaced periodically due to wear from striking the frizzen. The flintlock was widely used during the 18th and 19th centuries in both muskets and rifles.

Percussion cap

Percussion caps (caplock mechanisms), coming into wide service in the 19th century, were a dramatic improvement over flintlocks. With the percussion cap mechanism, the small primer charge of gunpowder used in all preceding small arms was replaced by a completely self-contained explosive charge contained in a small brass "cap". The cap was fastened to the touch hole of the gun (extended to form a "nipple") and ignited by the impact of the gun's "hammer". (The hammer is roughly the same as the cock found on flintlocks except that it doesn't clamp onto anything.) In the case of percussion caps the hammer was hollow on the end to fit around the cap in order to keep the cap from fragmenting and injuring the shooter. Once struck, the flame from the cap in turn ignited the main charge of gunpowder, as with the flintlock, but there was no longer any need to charge the touch hole with gunpowder, and even better, the touch hole was no longer exposed to the elements. As a result, the percussion cap mechanism was considerably safer, far more weatherproof, and vastly more reliable (cloth-bound cartridges containing a premeasured charge of gunpowder and a ball had been in regular military service for many years, but the exposed gunpowder in the entry to the touch hole had long been a source of misfires). All muzzleloaders manufactured since the second half of the 19th century use percussion caps except those built as replicas of the flintlock or earlier small arms.

Cartridges

A major innovation in small arms (and light artillery) came in the second half of the 19th century when ammunition, previously delivered as separate bullets and powder, was combined in a single metallic (almost always brass) cartridge containing a percussion cap, powder, and a bullet in one weatherproof package. Before this, a "cartridge" was simply a premeasured quantity of gunpowder together with a ball in a small cloth bag, which also acted as wadding for the charge and ball. This early form of cartridge had to be rammed into the muzzleloader's barrel, and either a small charge of gunpowder in the touch hole or an external percussion cap mounted on the touch hole ignited the gunpowder in the cartridge. Cartridges with built-in percussion caps (called "primers") continue to this day to be the standard in firearms. In cartridge-firing firearms, a hammer (or a firing pin struck by the hammer) strikes the cartridge primer, which then ignites the gunpowder within. The primer charge is at the base of the cartridge, either within the rim (a "rimfire" cartridge) or in a small percussion cap embedded in the center of the base (a "centerfire" cartridge). As a rule, centerfire cartridges are more powerful than rimfire cartridges, containing more gunpowder and (usually) larger diameter bullets.

Caseless cartridges are now being explored: instead of using brass as the cartridge case, these would hold the cartridge together with paper or some other substance that is destroyed when the gun is fired, eliminating the problem of brass casings ejecting and littering the ground. Caseless cartridges and the guns that would use them are still prototypes, although the idea of caseless cartridges can be traced to the musket "cartridges" widely used by the 18th-century military.

Nearly all contemporary firearms load cartridges directly into their breech. Some additionally or exclusively load from a magazine that holds multiple cartridges. A magazine is usually a box or cylinder that is designed to be reusable and is detachable from the gun. Some magazines, such as those of the Garand are internal to the firearm, and are loaded by using a clip, which is a device that looks like a rail holding the ammunition by the rim of the case. In most cases, a magazine and a clip are different in that the former's function is to feed ammunition into the firearm's breech, while the latter's is only to "charge" a magazine with fresh ammunition.