The Metallic Cartridge is a package that contains the components that constitute a firearm’s ammunition. These are one or more projectiles, a propellant, (typically black powder, Pyrodex, cordite or smokeless powder), and a primer all assembled into a unifying metallic case. The cartridge is designed in concert with a firearms manufacturer to allow safe operation of the cartridge in a suitable firearm. When a loaded metallic cartridge is properly loaded into a firearm it is ready to be fired using the necessary operation of that firearm (cocking, pulling the trigger etc.)
The metallic cartridge was developed in the late 19th century during a time of great expansion of industrial ability. It became an immediate success rendering all previous loading methods obsolete.
The first integrated cartridge was developed in Paris in 1808 by the Swiss gunsmith Jean Samuel Pauly in association with French gunsmith François Prélat. Pauly created the first fully self-contained cartridges: the cartridges incorporated a copper base with integrated mercury fulminate primer powder (the major innovation of Pauly), a round bullet and either brass or paper casing. The cartridge was loaded through the breech and fired with a needle. The needle-activated centerfire breech-loading gun would become a major feature of firearms thereafter. Pauly made an improved version, protected by a patent, on 29 September 1812.
Probably no invention connected with firearms has wrought such changes in the principle of gun construction as those effected by the “expansive cartridge case.” This invention has completely revolutionized the art of gun making, has been successfully applied to all descriptions of firearms, and has produced a new and important industry: that of cartridge manufacture.
One of the earliest efficient modern cartridge cases was the pinfire cartridge, developed by French gunsmith Casimir Lefaucheux in 1836. It consisted of a thin weak shell made of brass and paper that expanded from the force of the explosion. This fit perfectly in the barrel and thus formed an efficient gas check. A small percussion cap was placed in the middle of the base of the cartridge and was ignited by means of a brass pin projecting from the side and struck by the hammer. This pin also afforded the means of extracting the cartridge case. This cartridge was introduced in England by Lang, of Cockspur Street, London, about 1845.
French gunsmith Benjamin Houllier improved the Lefaucheux pinfire cardboard cartridge and patented in Paris in 1846, the first fully metallic pinfire cartridge containing powder (and a pinfire), in a metallic cartridge. He also included in his patent claims rim and centerfire primed cartridges using brass or copper casings. Houllier commercialised his weapons in association with the gunsmiths Blanchard or Charles Robert. Houllier creation of a cartridge case pressed from a sheet of brass or copper was a major innovation toward creating the metallic cartridge.
In 1856, the LeMat was the first American (French-designed) breech-loading revolver, but it used pinfire cartridges, not rimfire. These were sold in Europe, not the USA were the Pinfire never caught on.
In the United States, in 1857, the Flobert cartridge inspired the .22 Short (another rimfire), specially conceived for the first American revolver using rimfire cartridges, the Smith & Wesson Model 1.
Formerly, an employee of the Colt’s Patent Firearms Manufacturing Company, Rollin White, had been the first in America to conceive the idea of having the revolver cylinder bored through to accept metallic cartridges (circa 1852), with the first in the world to use bored-through cylinders probably having been Lefaucheux in 1845, who invented a pepperbox-revolver loaded from the rear using bored-through cylinders.
Samuel Colt refused this innovation. White left Colt, went to Smith & Wesson to rent a licence for his patent, and this is how the S&W Model 1 saw light of day in 1857. Today the Smith & Wesson Model 1 is known as .22 Short. The patent didn’t definitely expire until 1870, allowing Smith & Wesson competitors to design and commercialize their own revolving breech-loaders using metallic cartridges.
Famous models of that time are the Colts Open Top (1871-1872) and Single Action Army “Peacemaker” (1873). But in rifles, the lever-action mechanism patents were not obstructed by Rollin White’s patent infringement because White only held a patent concerning drilled cylinders and revolving mechanisms. Thus, larger caliber rimfire cartridges were soon introduced after 1857, when the Smith & Wesson .22 Short ammunition was introduced for the first time. Some of these rifle cartridges were used in the American Civil War, including the .44 Henry and 56-56 Spencer (both in 1860). However, the large rimfire cartridges were soon replaced by centerfire cartridges, which could safely handle higher pressures.
In 1860 American Benjamin Tyler used the same construction as Houllier adding a hollow rim that contained the primer mixture, thus creating the first rimfire cartridge. Coming at the time of the US Civil War the rimfire cartridge played a major role in that conflict. The .56 caliber Sharps rifle which could fire 14 rounds per minute allowed outnumbered troops to prevail on more than one occasion. This rifle and cartridge proved to be the decisive factor in Union troops defeating a much larger Confederate force.
Rimfire priming was a popular solution before centerfire priming was perfected. In a rimfire case, centrifugal force pushes a liquid priming compound into the internal recess of the folded rim as the manufacturer spins the case at a high rate and heats the spinning case to dry the priming compound mixture in place within the hollow cavity formed within the rim fold at the perimeter of the case interior. Large caliber rimfire cartridges were soon replaced by centerfire cartridges. Today only a few rimfire cartridges are still in use, mostly for use in small-caliber guns. These include the .17 Mach II, .17 Hornady Magnum Rimfire (HMR), 5mm Remington Magnum (Rem Mag), .22 (BB, CB, Short, Long, Long Rifle), and .22 Winchester Magnum Rimfire (WMR).
Compared to modern centerfire cases used in the strongest types of modern guns, existing rimfire cartridge designs use loads that generate relatively low pressure because of limitations of feasible gun design — the rim has little or no lateral support from the gun. Such support would require very close tolerances in design of the chamber, bolt, and firing pin. Because that is not cost-effective, it is necessary to keep rimfire load pressure low enough so that the stress generated by chamber pressure that would push the case rim outward cannot expand the rim significantly. Also, the wall of the folded rim must be thin and ductile enough to easily deform, as necessary to allow the blow from the firing pin to crush and thereby ignite the primer compound, and it must do so without rupturing, If it is too thick, it will be too resistant to deformation. If it is too hard, it will crack rather than deform. These two limitations — that the rim is self-supporting laterally and that the rim is thin and ductile enough to easily crush in response to the firing pin impact — limit rimfire pressures.
Modern centerfire cartridges are often loaded to about 62,000 psi (430,000 kPa) maximum chamber pressure. Conversely, no commercialized rimfire has ever been loaded above about 40,000 psi (280,000 kPa) maximum chamber pressure. However, with careful gun design and production, no fundamental reason exists that higher pressures could not be used. Despite the relative pressure disadvantage, modern rimfire cartridges include .17 HMR, 5mm, and .22-caliber generate muzzle energy comparable to smaller centerfire cartridges
Today, .22 LR (Long Rifle) accounts for the vast majority of all rimfire ammunition used. Standard .22 LR rounds use an essentially pure lead bullet plated with a typical 95% copper, 5% zinc combination. These are offered in supersonic and subsonic types, as well as target, plinking, and hunting versions. These bullets are usually coated with a hard wax for fouling control.
In 1857 the French Pottet cartridge was patented. It is the ancestor of the modern metallic cartridge.
The first widely used metallic cartridge case was patented by F.E. Schneider of Paris in England in 1861. These cartridges were sold by G.H. Daw in England. In 1868 Daw sued Eley for making a similar case. The case was thrown out which opened the door for widespread adoption of the metallic cartridge case.
In 1867 the British war office adopted the Eley-Boxer metallic centerfire cartridge case in the Pattern 1853 Enfield rifles, which were converted to Snider-Enfield breech-loaders on the Snider principle. This consisted of a block opening on a hinge, thus forming a false breech against which the cartridge rested. The priming cap was in the base of the cartridge, and was discharged by a striker passing through the breech block.
Other European powers adopted breech-loading military rifles from 1866 to 1868, with paper instead of metallic cartridge cases. The original Eley-Boxer cartridge case was made of thin-coiled brass—occasionally these cartridges could break apart and jam the breech with the unwound remains of the case upon firing. Later the solid-drawn, centerfire cartridge case, made of one entire solid piece of tough hard metal, an alloy of copper, with a solid head of thicker metal, has been generally substituted.
Colonel Hiram Berdan developed a system of drawing a brass case in 1870 that was markedly superior to other production methods of this time. He also developed a new type primer to be used in the brass case. This was a major advancement due to its lowering production costs. Berdan had also developed a primer for his case which is still widely found in European loaded ammunition. But the British Colonel Boxer’s primer is the dominant primer type in use today.
Some European- and Asian-manufactured military and sporting ammunition uses Berdan primers. Removing the spent primer from (decapping) these cases requires use of a special tool because the primer anvil (on which the primer compound is crushed) is an integral part of the case and the case, therefore, does not have a central hole through which a decapping tool can push the primer out from the inside, as is done with Boxer primers. In Berdan cases, the flash holes are located to the sides of the anvil. With the right tool and components, reloading Berdan-primed cases is perfectly feasible. However, Berdan primers are not readily available in the U.S.
In 1874 the French adopted the Fusil Model 1874 in 11mm in response to the Germans going to a metallic cartridge Mauwser 1871.
The 8mm Lebel (8 x 50R) was developed in 1886 and was the first modern metallic cartridge that used smokeless powder. It was in use until 1929.
Firearms cartridge names have three main areas of origination. These are: The United States of America (USA), United Kingdom (UK), and Europe. The USA and UK use the English measurement system while Europe and the rest of the world use the Metric measurement system. Additionally cartridge naming is affected by treaty organizations such as the North Atlantic Treaty Organization (NATO) which has its own conventions.
In general, cartridges can use the following elements in their naming:
There are at this time more than 3500 known cartridges, the vast majority of which are obsolete and no longer made or available. In the earliest days of cartridge development naming a cartridge was fairly simple. A cartridge name was often specified by its bullet diameter and the maker’s name. But there is little to no consistency in this. Part of the reason for this is “marketing” and part of the reason is copyright restrictions.
Many manufacturers developed the ability to produce ammunition. One occasion a particular cartridge would prove to be very popular, such as the .45 Long Colt used in the Colt “Peacemaker” handgun. Colt was not the only maker of ammunition. As long as the ammunition purchased for the handgun said .45 Long Colt on it there was a high degree of assurance that it would function in the Colt handgun safely.
Although most cartridges decimal number (such as .223 Rem, 5.56mm Nato) seems to be the bullet diameter, it often is not. Both .223 Rem and the 5.56mm Nato are the same basic cartridge, and both load a .224″ diameter bullet. There are dozens of .22 caliber cartridges which have diameters ranging from .220 to .224, sometimes the same cartridge name might have two different diameter bullets loaded for it.
The most common cartridges in use today tend to use their advertised bullet designation (such as .38 Special) and the makers name. The .38 Special is a Smith & Wesson designed bullet named as a .38 to distinguish it from an earlier less powerful .36 caliber from the same company. Both use .357 diameter bullets. A lengthened .38 Special was created for more power and named the .357 S&W Magnum. (the .38 Special will chamber and fire in a .357 Magnum revolver)
Names are often created simply to avoid confusion due to different makers offering very similar cartridges. The .22 Centerfire family is a good example. There are:
Just to name a few all of which use the same .224″ bullet. The cases and powder charges are often dramatically different.
In black powder rifle cartridges the bullet diameter is the first part of the cartridge name often followed by the weight of the powder charge (or the makers name), in grains. For example, the .50-90 Sharps has a .50-inch bullet and used a nominal charge of 90.0 grains (5.83 g) of black powder. The most used black powder metallic cartridge from the Mid 19th century in the US was the .56 Sharps.
Many such cartridges were designated by a three-number system, e.g., 45-120-3¼ Sharps: 45-caliber bullet, 120 grains of (black) powder, 3¼-inch long case. Other times a similar three-number system indicated caliber, charge (grains), and bullet weight (grains). The 45-70-500 Government is an example.
Handgun cartridges using black powder were those such as the .45 Long Colt, .44 Smith & Wesson Russian, etc. etc. The .45 Long Colt uses a bullet of .457″ diameter while the .45 ACP uses a bullet of .451″ diameter and many more, often using the same diameter bullet but assigning different caliber numbers.
In a modern caliber .44 Special was named that rather than its actual caliber of .429″. The .44 Magnum is also a .429″ diameter cartridge. (.44 Special will chamber and fire in a .44 Magnum revolver)
Often, the name reflects the company or individual who standardized it, such as the .30 Newton, or some characteristic important to that person. Sometimes the maker of the cartridge and the firearm don’t seem to be on the same page, even when this is the same company. There is confusion over the marking on the Winchester Model 94 which has .30 WCF stamped on the barrel. The boxes of cartridges (even those many by Winchester) say .30-30 on them.
The .30-’06 Springfield round is (nominally) a 0.308 inches (7.8 mm) military round designed at the Springfield arsenal in 1906. 7.92 x 57mm Mauser has a .323″ bullet diameter.
The .303 British is for a bore nominally 311/1000-inch and this chambering was standardized by the British Army.
Shotshells at one time were metallic cartridges. They use a multi-tiered naming system which looks like this: 12ga 2 3/4 Length 1330 Vel 1 1/4 Oz Shot 4 Shot size and in other cases they list the amount of powder in Drams or they may be quite simple such as 12 GA 2 3/4″ Buckshot 9 Pellets 00 Buck. Today shotshells are made mostly of polymer with a cosmetic band of metal around the base. Shotshells transitioned from being all metal, to a metal base with a paper body to a metal covering on a plastic body.
Shotshell wadding also transitioned from paper and wood to plastic in modern shells. They also became highly water resistant after the transition.
This illustration is of a rifle cartridge which has a primer cup which would be pressed into the base of the cartridge case prior to the case being filled with powder and bullet. This cartridge is a centerfire (based on the primer’s location) metallic cartridge.
The cartridge provides all the components necessary to load and fire a projectile from a firearm. It supports several purposes in doing so:
Many cartridges configurations of powder and bullet matched together to better address a specific task:
The firearm hobbyist who “loads” or “reloads” his own ammunition using the found basic components is called a “reloader.” This is done to obtain a wider selection of components, such as bullet, powder, and primer which can have the effect of lowering unit costs and/or increasing accuracy and/or effectiveness of the cartridge.
The cartridge case seals a firing chamber in all directions excepting the bore. A firing pin strikes the primer and ignites it. The primer compound deflagrates (that is, it rapidly burns); it does not detonate. A jet of burning gas from the primer ignites the propellant.
Gases from the burning powder pressurize and expand the case to seal it against the chamber wall. These propellant gases push on the bullet base. In response to this pressure, the bullet will move in the path of least resistance which is down the bore of the barrel. After the bullet leaves the barrel, the chamber pressure drops to atmospheric pressure. The case, which had been elastically expanded by chamber pressure, contracts slightly. This eases removal of the case from the chamber.
Brass is a commonly used case material because it is resistant to corrosion. A brass case head can be work-hardened to withstand the high pressures of cartridges, and allow for manipulation via extraction and ejection without tearing the metal. The neck and body portion of a brass case is easily annealed to make the case ductile enough to allow reforming so that it can be reloaded many times.
Steel is used in some plinking ammunition, as well as in some military ammunition (mainly from the former Soviet Union and China). Steel is less expensive than brass, but it is not feasible to reload and reuse steel cases. Military forces typically consider small arms cartridge cases to be disposable, one-time-use devices. However, case weight (mass) affects how much ammunition a soldier can carry, so the lighter steel cases do have a military advantage. Conversely, steel is more susceptible to contamination and damage so all such cases are varnished or otherwise sealed against the elements.
One downside caused by the increased strength of steel in the neck of these cases (compared to the annealed neck of a brass case) is that propellant gas can blow back past the neck and into the chamber. Constituents of these gases condense on the (relatively cold) chamber wall. This solid propellant residue can make extraction of fired cases difficult. This is less of a problem for small arms of the former Warsaw Pact nations, which were designed with much larger chamber tolerances than NATO weapons.
Aluminum cased cartridges are available commercially. These are generally not reloaded as aluminum fatigues easily during firing and resizing. Some calibers also have non-standard primer sizes to discourage reloaders from attempting to reuse these cases.
Plastic cases are commonly used in shotgun shells, and some manufacturers offer polymer centerfire cartridges.
Historically paper had been used in the earliest cartridges.
Critical cartridge specifications include neck size, bullet weight and caliber, maximum pressure, headspace, overall length, case body diameter and taper, shoulder design, rim type, etc. Generally, every characteristic of a specific cartridge type is tightly controlled and few types are interchangeable in any way. Exceptions do exist but generally, these are only where a shorter cylindrical rimmed cartridge can be used in a longer chamber, (e.g., .22 Short in .22 Long Rifle chamber, and .38 Special in a .357 Magnum chamber). Centerfire primer type (Boxer or Berdan, see below) is interchangeable, although not in the same case. Deviation in any of these specifications can result in firearm damage and, in some instances, injury or death. Similarly, use of the wrong type of cartridge in any given gun can damage the gun, or cause bodily injury.
Cartridge specifications are determined by several standards organizations, including SAAMI in the United States, and C.I.P. in many European states. NATO also performs its own tests for military cartridges for its member nations; due to differences in testing methods, NATO cartridges (headstamped with the NATO cross) may present an unsafe combination when loaded into a weapon chambered for a cartridge certified by one of the other testing bodies. 
Bullet diameter is measured either as a fraction of an inch (usually in 1/100 or in 1/1000) or in millimetres. Cartridge case length can also be designated in inches or millimetres.
Metallic cartridges have a rim on the base of the cartridge. The purchase of the rim can be to restrict how far the cartridge case is inserted into the chamber and also serves to provide a groove by which a claw (called and extractor) or similar device can gain purchase to pull a spent cartridge from the chamber. Rimfire cartridges have their primer mixture contained within the rim also.
Most revolver cartridges have a rim at the base of the case that is larger than the case body is and which seats against or into the cylinder block to provide headspace control (to keep the cartridge from moving too far forward in the cylinder chamber) and to provide for easy extraction. Some rimmed cartridges (the rimfire type) also have the primer contained within the rim. Example: .45 Colt Revolvers can use rimless ammunition by means of a “half moon clip.” Examples of cartridges that can be used this way are 9mm Luger and .45 ACP.
The semi-rimmed has a less prominent rim than the standard rimmed cartridge. Like rimmed the function of case extraction is performed on the rim. Semi-rimmed cartridges are typically headspaced on the rim. An example of a modern cartridge which is semi-rimmed is the .220 Swift.
A “rimless” cartridge case has a rim that is the same diameter as the case body. It is not actually rimless. Example: .223 Rem
Rarely found is the rebated rim. In the rebated rim the cartridge case is larger than the rim. This can allow a smaller bolt face in a bolt action rifle to be used with a larger diameter case of ammunition. Example: .284 Winchester
The belted cartridge is most often associated with a “belted magnum.” In a belted cartridge the headspacing is controlled by the location of the belt. Example: 7mm Remington Magnum
The design of a bullet for one type of firearm is not necessarily appropriate for another type of firearm. Just as rim types are most effective in firearms of an appropriate so are bullets loaded into cartridges. Bullets are often described by their shape, their material composition, and sometimes by a brand that suggests a particular quality of use.
Bullet types based on shape include:
Shotguns do not use the terminology of bullet. The round balls in a shotgun shell are pellets. The large solid bullets are slugs.
Some bullet types work better in revolvers, but not in self loading handguns. The self-loaders may have jamming problems with cartridges that have exposed lead bullets. Revolvers are not as sensitive to the power load of cartridges and can also load short cartridges of lower power in the same cylinder diameters (many examples exist).
Cartridges most often used in Revolvers tend to have bullets that are:
Self-loading handguns, usually called Semi-Automatic and also sometimes incorrectly called automatic handguns function more reliably with cartridge types that do not have exposed lead bullets. Semi-automatic handguns are power level sensitive and unlike revolvers will fail to self reload if the power of a cartridge is too low (of if the cartridge powder has deteriorated due to moisture or oil vavpor). A typical failure with lead bullets is the Failure To Feed (FTE) and with low power cartridges is Failure to Eject (FTE). These types of failures can also be cause by lacquer coated cartridges which are sometimes found which have been loaded to military specifications of some nations.
Shotguns are usually used to fire a number of pellets, although they can also fire a single pellet known as a slug. Shotguns may use multiple barrels with different amounts of constriction of the bore (called Choke) to control the pattern of distribution of pellets at range. Double barreled and over/under designs are popular for this reason as they can have two different choke amounts in a single gun, proving a short range and a longer range pattern for improved hit ability.
The pellets and slugs are offered in different sizes and with different powder load levels. Boxes of shotshells typically list the Gauge, length, Pellet Size, Powder Charge, shot material, and sometimes the velocity of the shot at the muzzle.
Shotgun pellets described by a Number which corresponds to their diameter and are divided into four basic types:
Shotguns are chambered in several different “calibers.” They are:
Shotshells are also made in different lengths:
There are a number of special shotshell types.
There is no question that the firearm came first and the cartridge was designed to fit it later. With hundreds of manufacturers all trying to produce firearms and munitions there was a great deal of copying of designs. Fortunately there are very few monopolies in the production of ammunition. So there are many makers producing the same cartridge for the same guns. When they designs of these cartridges are established and well controlled there is no problem. Organizations such as SAAMI and CIP exist to ensure safety from one make of ammunition to another. There are however still safety issues.
The nature of a cartridge is that it can accept different components. The four basic components are:
When they are carefully combined a safe to use cartridge exists. Makers of ammunition offer cartridges with many choices of components. The only one of the four basic components that is very stable is the case. There are two types of cases (Berdan and Boxer Primed) which appear identical. The primers for these cases cannot be interchanged.
The other three components are often available in different specifications. Bullets can have dozens of shapes, constructions, and weights. There are dozens of powders which have different burn characteristics which are suitable to a limited number of cartridge and bullet configurations. And there is some variation in the efficiency of the primers used as well.
For the shooter wanting to shoot a firearms the correct cartridge must be known. Sometimes this is confusing. The Winchester Model 94, is one of the most popular lever action rifles in history. It’s barrel says it’s in the .30 WCF caliber. But this caliber is not found in sporting goods stores. There is is called .30-30 Winchester.
Some hazards exist for the unwary ammunition buyer. Two popular cartridges measure 9 x 19mm and look identical but are for different types of guns. The 9 x 19mm Luger cartridge is suitable for almost any gun of that caliber. But the 9mm Luger cartridge must never be fired in a 9mm Glisenti although it is a perfect fit. The 9mm Luger has 25 to 30% higher operating pressure and could cause an explosion.
There are less obvious problems with cartridge safety where guns themselves need to be restricted to certain pressures. Using 9 x 19mm Luger as an example: the SAAMI recommended maximum pressure is 34,000 psi. But some cartridges are loaded to much higher pressures. The ammunition in these cases may carry a Plus P or even a Plus P Plus designation. Pressures in 9mm Luger can go as high as 42 to 44, 000 psi. The higher pressures produce far more powerful ammunition. But not all modern guns are engineered for these pressure levels. A firearms owner MUST always know what his gun is rated for.
There are also some cartridges that will “chamber” in some firearms for which they are not designed. While we may think this doesn’t happen, careless users blown a gun almost every week by inserting a cartridge that they think fits but is wrong.
Cartridges can suffer a number of failure types:
Note that the same types of failures that occur in self loaders, affect all types of self loaders whether handgun, rifle, or shotgun so references to one apply to all.
Wildlife in many areas have been depleted due to the effects of lead poisoning from fired cartridges. New bullet materials are being used that do not contain lead. Many shooting ranges are shutting down due to lead contamination in the air from fired bullets that contain lead. Some are having new ventilation systems installed to meet safety standards.
Cartridge makers are addressing these concerns with cartridges whose projectiles do not use lead such as:
The Hague Convention of 1899 bans the use of expanding projectiles against the military forces of other nations. Some countries accept this as a blanket ban against the use of expanding projectiles against anyone, while others use JSP and HP against non-military forces such as terrorists and criminals
Ammunition types are listed numerically.
Soon after the development of the lead bullet came the rifles which were often used to take game, both large and small. From the very early days the cost of ammunition is considerable. Early cartridges could be reused by replacing the primer, powder and bullet at a major cost reduction using simple hand equipment and bullet casting molds. In the 19th century the cost of lead was so dear that bounty killer who were eliminating the American Bison for hides, would still dig out their bullets because of their extreme cost.
Several companies made tools by which a typical hunter could easily reload his own cartridges. Powder, Primer, and when needed cases and bullets were available, but often after a long wait. Lead bullets that were damaged could easily be remelted and cast in bullet molds to be reused in making cartridges. This process is called handloading.
Movie reference where this is illustrated: Valdez is Coming
Some shooting enthusiasts reload their fired brass cases and plastic, paper, or brass shotgun shells. By using a press and a set of dies, one can reshape, deprime, reprime, recharge the case with gunpowder, and seat and crimp a new bullet (or shot charge) in place. One can do this at a lower cost than that of factory ammunition partly because the case represents a significant portion of the total cost of a round. Reloading also allows one to use different weights and shapes of bullets, as well as varying the powder type and charge, which affects accuracy and power. Enthusiasts usually only reload boxer primed cases as this reloading process is more easily automated than Berdan priming is. Berdan primed cases have to have the pocket reamed before use.
There are many companies engaged in firearms and weapons development who are trying to devise ever more effective and efficient systems. Some of these developments have achieved some recognition:
The Salvo project experimented with using two or more bullets loaded into 7.62mm cartridges.
Special Purpose Individual Weapon development produced a new type of projectile called a fletchette for use in small arms.
Many governments and companies continue to develop caseless ammunition (where the entire case assembly is either consumed when the round fires or whatever remains is ejected with the bullet). So far, none of these have been successful enough to reach the civilian market and gain commercial success. Even within the military market, use is limited. Around 1848, Sharps introduced a rifle and paper cartridge (containing everything but the primer) system. When new these guns had significant gas leaks at the chamber end, and with use these leaks progressively worsened. This problem plagues caseless cartridge and gun systems to this day.
The Daisy Heddon VL Single Shot Rifle, which used a caseless round in .22 caliber, was produced by the air gun company, beginning in 1968. Apparently Daisy never considered the gun an actual firearm. In 1969, the ATF ruled it was, in fact, a firearm, which Daisy was not licensed to produce. Production of the guns and the ammo was discontinued in 1969. They are still available on the secondary market, mainly as collector items, as most owners report that accuracy is not very good.
In 1989, Heckler & Koch, a prominent German firearms manufacturer, began advertising the G11 assault rifle, which shot a 4.73×33 square caseless round. The round was mechanically fired, with an integral primer.
In 1993 Voere of Austria began selling a the Voere VEC91 rifle, and 5.7 and 6mm and caseless ammunition. Their system used a primer, electronically fired at 17.5 ± 2 volts. The upper and lower limits prevent fire from either stray currents or static electricity. The direct electrical firing eliminates the mechanical delays associated with a striker, reducing lock time, and allowing for easier adjustment of the rifle trigger.
In both instances, the “case” was molded directly from solid nitrocellulose, which is itself relatively strong and inert. The bullet and primer were glued into the propellant block.
2000, US LSAT rifle and carbine under development using the same propellant from the HKG11.
Problems such as obturation, flame cutting, fragile ammunition, and cookoff and other problems with the actual use of caseless ammunition are cited as to the reasons this technology has not been adopted. 
The “Tround” (“Triangular Round”) was a unique type of cartridge designed in 1958 by David Dardick, for use in specially designed Dardick 1100 and Dardick 1500 open-chamber firearms. As their name suggests, Trounds were triangular in cross-section, and were made of plastic or aluminum, with the cartridge completely encasing the powder and projectile. The Tround design was also produced as a cartridge adaptor, to allow conventional .38 Special and 22 Long Rifle cartridges to be used with the Dardick firearms.
A blank is a charged cartridge that does contain a projectile that is intended to cause injury. A blank cartridges exist in several configurations.
Although not intended to injure or kill, blank ammunition can cause injuries or fatalities when used incorrectly. Blank ammunition can cause the same hearing damage as a live firearm discharge.
Drill rounds are inert versions of cartridges used for education and practice during military training. Other than the lack of propellant and primer, these are the same size as normal cartridges and will fit into the mechanism of a gun in the same way as a live cartridge does. Training rounds are often brightly colored to distinguish them from “live” rounds. They are used to teach the manual of arms of a particular weapon.
Practice rounds are also used to develop fine trigger control in shooters. The practice of pulling the trigger of an unloaded firearm which has its mechanism “cocked” will cause the firing pin or striker to hit the mechanical limits built within the mechanism. Repeated actions of this type will cause damage, sometimes breaking or damaging a firing pin (or striker) which will require repair. Dummy rounds called snap caps, or manipulation rounds are used to protect centerfire guns from possible damage during “dry-fire” trigger control practices. They load in the normal fashion but will not fire and will not cycle a firearm. They must be loaded manually. They are generally designed as a facsimile of the usual case design and will usually extract normally when the gun is operated by hand.
To distinguish drill rounds and snap-caps from live rounds these are marked distinctively. Several forms of markings are used; e.g. setting colored flutes in the case, drilling holes through the case, coloring the bullet or cartridge, or a combination of these. In the case of centerfire drill rounds the primer will often be absent, its mounting hole in the base is left open. Because these are mechanically identical to live rounds, which are intended to be loaded once, fired and then discarded, drill rounds have a tendency to become significantly worn and damaged with repeated passage through magazines and firing mechanisms, and must be frequently inspected to ensure that these are not so degraded as to be unusable—for example the cases can become torn or misshapen and snag on moving parts, or the bullet can become separated and stay in the breech when the case is ejected.
The bright-colored Mek-Porek is an inert cartridge base designed to prevent a live round from being unintentionally chambered, to reduce the chances of an accidental discharge from mechanical or operator failure. An L-shaped flag is visible from the outside, so that the shooter and other people concerned are instantly aware about the situation of the weapon. The Mek-Porek is usually tethered to its weapon by a short string, and can be quickly ejected to make way for a live round if the situation suddenly warrants. This safety device is planned to become standard-issue in the Israel Defense Forces.