Selective fire means the capability of a weapon to be adjusted to fire in semi-automatic, burst mode, and/or fully automatic firing mode.The modes are chosen by means of a selector switch, which varies depending on the weapon's design. Some selective-fire weapons have burst fire mechanisms to limit the maximum number of shots fired automatically in this mode. The most common limits are two or three rounds per trigger pull. Fully automatic fire refers to the ability for a weapon to fire continuously until either the feeding mechanism is emptied or the trigger is released. Semi-automatic refers to the ability to fire one round per trigger pull.
The presence of selective fire modes on firearms permits more efficient use of rounds to be fired for specific needs, versus having a single mode of operation, such as fully automatic, thereby conserving ammunition while maximizing on-target accuracy and effectiveness. This capability is most commonly found on military weapons of the 20th and 21st centuries.
Early attempts at this technology were hindered by one or both of two obstacles: over-powerful ammunition and mechanical complexity. The latter led to excessive weight and unreliability in the firearm.One of the earliest designs dates to just before the end of the 19th century with the development of the Cei-Rigotti, an early automatic rifle created by Italian Army officer Amerigo Cei-Rigotti that had selective-fire capability (single shots or burst).
Another is the M1918 Browning Automatic Rifle (BAR) developed during the First World War. The BAR and its subsequent designs incorporated a variety of selective-fire functions. The first design (M1918) is a selective-fire, air-cooled automatic rifle that used a trigger mechanism with a fire selector lever that enabled operating in either semi-automatic or fully automatic firing modes. The selector lever is located on the left side of the receiver and is simultaneously the manual safety (selector lever in the "S" position – weapon is "safe", "F" – "Fire", "A" – "Automatic" fire). 225–226 The next version (M1918A1) had a unique rate-of-fire reducer mechanism purchased from FN Herstal with two rates of automatic fire. This reducer mechanism was later changed to one designed by the Springfield Armory. The final version (M1918A2) provided two selectable rates of fully automatic fire only. :131–139:
During World War II the Germans began development of the selective-fire function which resulted in the FG 42 battle rifle developed in 1942 at the request of the German Air Force ( Luftwaffe ) in 1941.Another German design that used selective fire was the StG 44 that was the first of its kind to see major deployment and is considered by many historians to be the first modern assault rifle. "The principle of this weapon -- the reduction of muzzle impulse to get useful automatic fire within actual ranges of combat -- was probably the most important advance in small arms since the invention of smokeless powder."
The selective-fire function was later seen in the Russian AK-47 (designed in 1946), the Belgian FN FAL (designed 1947-53) the British EM-2 (designed in 1948), and the U.S. AR-10 (designed in 1957) and its AR derivatives.
Selective-fire weapons, by definition, have a semi-automatic mode, where the weapon automatically reloads the chamber after each fired round, but requires the trigger be released and pulled again before firing the next round. This allows for rapid and (in theory) aimed fire.In some weapons, the selection is between different rates of automatic fire and/or varying burst limiters. The selection is often by a small rotating switch often integrated with the safety catch or a switch separate from the safety, as in the British SA80 family. Another method is a weighted trigger, such as the Steyr AUG, which will fire a single shot when 4.0 - 7.1 kg (8.8 – 15.4 lbs.) of weight is exerted on the trigger, and then become fully automatic when over 7.1 kg (15.4 lbs.) of weight is applied. This is useful for emergency situations where a rapid volley of rounds is more effective for suppressing a close enemy rather than a single-round burst.
Some selective-fire weapons offer a burst mode as the second option, where each pull of the trigger automatically fires a predetermined number of rounds (generally two or three), but will not fire any more until the trigger is pulled again.The current U.S. standard assault rifle, the M16A4, and the M4 carbine variant of this rifle fire a maximum of three rounds with each pull of the trigger in burst mode. In this design, it retains the count of previously fired rounds and may fire fewer than three rounds. Other designs reset the count with each trigger pull, allowing a uniform three-round burst as long as rounds remain.
A common version of the Heckler & Koch MP5 submachine gun (which is widely used by SWAT teams and military special operations personnel) fires single shots, three-round-bursts, and automatically. A special variant uses a two-round-burst to minimize the chances of missing with a third round. Some automatic cannons have larger burst limiters to coincide with higher rates of fire.
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries.
A machine pistol is a self-loading pistol capable of burst or fully automatic fire. It can also be used to describe a stockless handgun-style submachine gun. The term is a calque of Maschinenpistole, the German word for submachine guns. Machine pistols were developed during World War I and originally issued to German artillery crews who needed a self-defense weapon that is lighter than a rifle but more powerful than a standard semi-automatic pistol. Today, they are considered a special purpose weapon with limited utility, and without a shoulder stock, difficult to control for all but the best shooters.
A semi-automatic rifle is a rifle that fires a single bullet with each pull of the trigger. For comparison, a bolt action rifle requires the user to cycle the bolt manually before they can fire a second time, and a fully automatic rifle, provided it has ammunition, will continue to fire until the trigger is released. Most modern automatic rifles are selective fire, meaning the user can fire semi-automatically if desired.
The Colt AR-15 is a lightweight, magazine-fed, gas-operated semi-automatic rifle. The "AR” stands for the first two letters of ArmaLite. It was designed with the extensive use of aluminum alloys and synthetic materials in order to reduce weight. Colt's Manufacturing Company currently uses the AR-15 trademark for its line of semi-automatic AR-15 rifles.
A semi-automatic firearm, also called a self-loading or autoloading firearm, is a repeating firearm whose action mechanism automatically loads a following round of cartridge into the chamber (self-loading) and prepares it for subsequent firing, but requires the shooter to manually actuate the trigger in order to discharge each shot. Typically, this involves the weapon's action utilizing the excess energy released during the preceding shot to unlock and move the bolt, extracting and ejecting the spent cartridge case from the chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber, all without input from the user. To fire again, however, the user must actively release the trigger, allow it to "reset", before pulling the trigger again to fire off the next round. As a result, each trigger-pull only discharges a single round from a semi-automatic weapon, as opposed to a fully automatic weapon, which will shoot continuously as long as the ammunition is replete and the trigger is kept depressed.
A semi-automatic pistol is a type of repeating single-chamber handgun (pistol) that automatically cycles its action to insert the subsequent cartridge into the chamber (self-loading), but requires manual actuation of the trigger to actually discharge the following shot. As a result, only one round of ammunition is fired each time the trigger is pulled, as the pistol's fire control group disconnects the trigger mechanism from the firing pin/striker until the trigger has been released and reset.
An automatic firearm is a firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. The action of an automatic firearm is capable of harvesting the excess energy released from a previous discharge to feed a new ammunition round into the chamber, and then ignite the propellant and discharge the projectile by delivering a hammer/striker impact on the primer.
The Special Purpose Individual Weapon (SPIW) was a long-running United States Army program to develop, in part, a workable flechette-firing "rifle", though other concepts were also involved. The concepts continued to be tested under the Future Rifle Program and again in the 1980s under the Advanced Combat Rifle program, but neither program resulted in a system useful enough to warrant replacing the M16.
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. This can be influenced by several factors, including operator training level, mechanical limitations, ammunition availability, and weapon condition. In modern weaponry, it is usually measured in rounds per minute or rounds per second.
The Cei-Rigotti is an early automatic rifle created in the final years of the 19th century by Amerigo Cei-Rigotti, an officer in the Royal Italian Army. Although the rifle was never officially adopted by any military, it was tested extensively by the Italian Army during the lead-up to the First World War.
The karabinek wzór 1988 Tantal is a 5.45×39mm assault rifle designed and produced in Poland in the late 1980s.
The Type 95 Automatic Rifle or QBZ-95 is a bullpup assault rifle designed and manufactured by Norinco, and issued since 1995 as the service rifle for the People's Liberation Army, People's Armed Police and various paramilitary law enforcement agencies in the People's Republic of China. The rifle's designation "QBZ" stands for "light weapon - rifle (Bùqiāng) - automatic (Zìdòng)", in keeping with the coding standards of the Chinese defense industry.
The AEK-971 is a selective fire 5.45×39mm assault rifle that was developed at the Kovrov Mechanical Plant (KMZ) by chief designer Sergey Koksharov in the late 1970s and 1980s.
A self-loading rifle or autoloading rifle is a rifle with an action using a portion of the energy of each cartridge fired to load another cartridge. Self-loading pistols are similar, but intended to be held and fired by a single hand, while rifles are designed to be held with both hands and fired from the shoulder.
A trigger is a mechanism that actuates the function of a ranged weapon such as a firearm, airgun, crossbow, or speargun. The word may also be used to describe a switch that initiates the operation of other non-shooting devices such as a trap, a power tool or a quick release. A small amount of energy applied to the trigger leads to the release of much more energy.
In automatic firearms, burst mode or burst-fire is a firing mode enabling the shooter to fire a predetermined number of rounds, usually two or three rounds on hand held weapons and 50-100+ on anti-aircraft weapons and autocannons, with a single pull of the trigger. This firing mode is commonly used in submachine guns and assault rifles. Other types of firearms, such as machine pistols, e.g., the Heckler & Koch VP70 and Beretta 93R also have a burst mode.
The Model L is a Spanish 5.56×45mm NATO assault rifle developed in the late 1970s at the state-owned small arms research and development establishment CETME located in Madrid. The rifle retains many of the proven design elements the institute had used previously in its CETME Model 58 battle rifles.
The ČZ 2000 is a prototype 5.56 mm caliber Czech weapon system, consisting of a standard rifle, carbine and light machine gun. The system was developed in 1991 after adapting the LADA firearm prototype J. Denel from the Brno-based Prototypa-ZM company is the chief designer for both systems. The ČZ 2000 was to be produced by Česká zbrojovka of Uherský Brod. It was planned to be the new service weapon of the Czech Army, replacing: the 7.62 mm vz. 58 assault rifle, 7.65 mm vz. 61 Škorpion submachine gun and 7.62 mm vz. 59 machine gun. As of 2007, the project has been discontinued.
The following are terms related to firearms and ammunition topics.
The Norinco Type 80 is a close-combat machine pistol that was used in China in the 1980s by the People's Liberation Army of China. It was developed by Norinco in the 1970s, influenced by the design of the German M712 Schnellfeuer. The Type 80 can be used in either single-shot mode or fully automatic fire mode; however, the chamber overheats after ten rounds of sustained automatic fire, risking accidental discharge.