Caseless ammunition Caseless ammunition is a type of small arms ammunition that eliminates the cartridge case that typically holds the primer , propellant , and projectile together as a unit . Caseless ammunition is an attempt to reduce the weight and cost of ammunition by dispensing with the case , which is typically precision made of brass or steel , as well as simplify the operation of repeating firearms by eliminating the need to extract and eject the empty case after firing . History . Caseless ammunition , in the broad sense , is not a new concept . A number of early paper cartridge designs used a combustible " case " , which left no significant residue in the action after firing ; one of the earliest military breech - loading rifles , the Dreyse needle gun , used such a cartridge . It contained the powder , primer , and sabot ed bullet in a paper cartridge . This design was an evolution of earlier paper cartridges for externally primed muzzle loading firearms , and predated the wide adoption of the metallic cartridge case . The first use of caseless ammunition for use in a repeating firearm was the Rocket Ball projectile patented by Walter Hunt in 1848 . A charge of black powder was placed inside a hollow at the back of a specially shaped Minié ball . These rounds were used by Hunt in a prototype repeating lever action rifle . The later Volcanic cartridge by Smith & Wesson added a primer to the Rocket Ball , and improved on the lever action design . Similar ammunition was used by the Volcanic Repeating Arms company for the Volcanic rifle . During World War II , Germany began an intensive program to research and develop a practical caseless ammunition for military use , which was driven by the rising scarcity of metals , especially copper used to make cartridge cases . The Germans had some success , but not sufficient to produce a caseless cartridge system during the war . Modern caseless ammunition . Modern caseless ammunition consists of a solid mass of propellant , originally nitrocellulose , cast into shape to form the body of the cartridge , with cavities to accept the bullet and a primer , preferably combustible , which are glued into place . The completed cartridge might also contain a booster charge of powdered propellant , to help ignite the body and provide initial thrust to the bullet . Many caseless cartridges are also telescoped , with the bulk of the bullet held within the body of the cartridge , to cut down on cartridge length . A shorter cartridge cuts down on the distance the firearm ' s action must reciprocate to load a new round , which allows for higher cyclic rates and greater probability of multiple hits on a target at long range . Lack of a case also reduces the weight of the cartridge substantially , especially in small bore rifles . For example , the caseless ammunition for the Voere VEC - 91 weighs about one third as much as regular ammunition for the same caliber . While it seems a simple operation to replace the case with a piece of solid propellant , the cartridge case provides more than just a way to keep the cartridge components together , and these other functions must be replaced if the case is to be replaced . Caseless ammunition is not without its drawbacks , and it is these drawbacks that have kept modern caseless ammunition from achieving wider success . Heat sensitivity . The first major problem , of special concern in military applications , which often involve sustained firing , is the heat sensitivity of the ammunition . Nitrocellulose , the primary component of modern gunpowder , ignites at a relatively low temperature of around 170 °C ( 338 °F ) . One of the functions of the metallic cartridge case is as a heat sink ; when extracted after firing , every metallic case carries away a significant amount of the heat from the combustion of the propellant , slowing the rate at which heat builds up in the chamber . The thermal insulation provided by the case also works the other way around , shielding the propellant from built - up heat in the chamber walls . Without a case to provide these functions , caseless rounds using nitrocellulose will begin to cook off , firing from the residual chamber heat , much sooner than cased cartridges do . The normal solution to the problem of heat is to increase the heat resistance by switching to a propellant with a higher ignition temperature , typically a non - crystalline explosive carefully formulated to provide an appropriate rate of combustion . Heckler & Koch , in concert with Dynamit Nobel , managed such a task by producing relatively heat - resistant caseless ammunition . Sealing . Another important function provided by the cartridge is to seal the rear of the chamber . During firing of a cased cartridge , the pressure in the chamber expands the brass and blocks the chamber . This prevents gas exiting from the rear of the chamber , and it has also been experimentally shown to provide a significant amount of support to the bolt . Without the case to provide this seal , the firearm design must account for this and provide a means of sealing the rear of the chamber . This problem was also encountered with the Dreyse needle gun ; the French Chassepot solved the leaking - breech problem with the addition of a rubber seal to the bolt . Telescoping caseless rounds must also deal with the issue of blocking the bore , as the bullet is surrounded by propellant . The booster charge is used to address this issue , providing an initial burst of pressure to force the bullet out of the cartridge body and into the barrel before the body combusts . Fragility . Caseless rounds are limited by the fact that the cartridge body is primarily a propellant , and structural properties are secondary to the combustion properties . The primary issue is one of extraction . While caseless ammunition eliminates the need to extract a fired case , unfired cases must be extracted in case of a misfire , or to unload the firearm . In metallic cases , this ability is provided by a rim or extractor groove machined into the rear of the case . Even in completely plastic bodied cartridges , such as the " Activ " brand shotgun shell s , a thin metal ring is molded into the rim to provide support for the extractor . Modern caseless firearms . One of the first caseless firearm and ammunition systems produced was actually made by Daisy , the airgun maker , in 1968 . The Daisy V / L Rifle used a . 22 caliber ( 5 . 5 mm ) low powered caseless round with no primer . The rifle was basically a spring - piston air rifle , but when used with the V / L ammunition the energy from the compression of the piston heated the air behind the caseless cartridge enough to ignite the propellant , and this generated the bulk of the energy of firing . The Daisy V / L Rifle system was discontinued in 1969 after the ATF ruled that it was not an airgun , but a firearm , which Daisy was not licensed to produce . Several assault rifle s have used caseless ammunition . One of the better - known weapons of this type is the G11 made by Heckler & Koch . Although the rifle never entered full production , it went through a number of prototype stages as well as field testing before being put aside in favour of a more conventional firearm , the G36 , which was also cheaper . The first commercial caseless rifle featuring electronic firing was the Voere VEC - 91 .