A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and used by an individual. The term is legally defined further in different countries.
The National Firearms Act (NFA), 73rd Congress, Sess. 2, ch. 757, 48 Stat. 1236 was enacted on June 26, 1934, and currently codified and amended as I.R.C. ch. 53. The law is an Act of Congress in the United States that, in general, imposes an excise tax on the manufacture and transfer of certain firearms and mandates the registration of those firearms. The NFA is also referred to as Title II of the federal firearms laws, with the Gun Control Act of 1968 ("GCA") as Title I.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), commonly referred to as the ATF, is a domestic law enforcement agency within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use, manufacture, and possession of firearms and explosives; acts of arson and bombings; and illegal trafficking and tax evasion of alcohol and tobacco products. The ATF also regulates via licensing the sale, possession, and transportation of firearms, ammunition, and explosives in interstate commerce. Many of the ATF's activities are carried out in conjunction with task forces made up of state and local law enforcement officers, such as Project Safe Neighborhoods. The ATF operates a unique fire research laboratory in Beltsville, Maryland, where full-scale mock-ups of criminal arson can be reconstructed. The ATF had 5,285 employees and an annual budget of almost $1.5 billion in 2021. The ATF has received criticism over its handling of the Ruby Ridge siege, the Waco siege and other incidents.
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 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, and 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.
In firearms terminology and at law, the firearm frame or receiver is the part of a firearm which integrates other components by providing housing for internal action components such as the hammer, bolt or breechblock, firing pin and extractor, and has threaded interfaces for externally attaching ("receiving") components such as the barrel, stock, trigger mechanism and iron/optical sights. Various firearm receivers often come with 1 or 2 sections, the upper receiver which houses the barrel/trunnion, bolt components etc and the lower receiver that holds the fire control group, pistol grip, selector, stock etc.
The Waco siege, also known as the Waco massacre, was the siege by U.S. federal government and Texas state law enforcement officials of a compound belonging to the religious cult known as the Branch Davidians, between February 28 and April 19, 1993. The Branch Davidians, led by David Koresh, were headquartered at Mount Carmel Center ranch in unincorporated McLennan County, Texas, 13 miles northeast of Waco. Suspecting the group of stockpiling illegal weapons, the Bureau of Alcohol, Tobacco, and Firearms (ATF) obtained a search warrant for the compound and arrest warrants for Koresh and several of the group's members.
An automatic firearm or fully automatic firearm is a self-loading 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 igniting the propellant and discharging the projectile by delivering a hammer or striker impact on the primer.
A hell-fire trigger is a device that allows a semi-automatic firearm to fire at an increased rate. The hell-fire clamps to the trigger guard behind the trigger and presses a "finger" against the back of the trigger to increase the force that returns the trigger to its forward position, effectively decreasing the time required for the trigger to reset, allowing for a faster follow up shot.
A firearm is said to fire from an open bolt or open breech if, when ready to fire, the bolt and working parts are held to the rear of the receiver, with no round in the chamber. When the trigger is actuated, the bolt travels forward, feeds a cartridge from the magazine or belt into the chamber, and fires that cartridge in the same movement. Like any other self-loading design, the action is cycled by the energy released from the propellant, which sends the bolt back to the rear, compressing the mainspring in readiness for firing the next round. In an open-bolt gun firing semi-automatically, the bolt is caught and held at this point by the sear after each shot; and in automatic open-bolt fire, it's caught and held in this manner whenever the trigger is released. In contrast to this, in closed-bolt guns, the trigger and sear do not affect the movement of the bolt directly.
The Firearm Owners' Protection Act (FOPA) of 1986 is a United States federal law that revised many provisions of the Gun Control Act of 1968.
Bump stocks or bump fire stocks are gun stocks that can be used to assist in bump firing, the act of using the recoil of a semi-automatic firearm to fire cartridges in rapid succession.
Dry firing is the act of activating the firing mechanism a bow, crossbow, firearm or other projectile discharging weapon while unloaded or without live ammunition. The expression is also used to refer to practicing with an inert laser/infrared training platform and may also include the use of a target/feedback system.
In the United States, the right to keep and bear arms is modulated by a variety of state and federal statutes. These laws generally regulate the manufacture, trade, possession, transfer, record keeping, transport, and destruction of firearms, ammunition, and firearms accessories. They are enforced by state, local and the federal agencies which include the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).
Title II weapons, or NFA firearms, are designations of certain weapons under the United States National Firearms Act (NFA).
A homemade firearm, also called a ghost gun or privately made firearm, is a firearm made by a private individual, in contrast to one produced by a corporate or government entity. The term "ghost gun" is used mostly in the United States by gun control advocates, but it is being adopted by gun rights advocates and the firearm industry.
A Glock switch is a small device that can be attached to the rear of the slide of a Glock handgun, converting the semi-automatic pistol into a selective fire machine pistol capable of fully automatic fire. As a type of auto sear, it functions by applying force to the trigger bar to prevent it from limiting fire to one round of ammunition per trigger pull. This device by itself, regardless if it is installed on a slide or not, is considered by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to be a machine gun, making possession of the device illegal in the United States under most circumstances.
Garland v. Cargill, 602 U.S. 406 (2024), was a United States Supreme Court case regarding the classification of bump stocks as "machine guns" under the National Firearms Act of 1934 (NFA) by the United States Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) in 2018. In a 6-3 decision, the Supreme Court ruled that bump stocks are not machine guns for purposes of the NFA, vacating the ATF rule and finding that the ATF exceeded its statutory authority.
A binary trigger is a device that allows a semi-automatic firearm to fire at an increased rate. The binary trigger works by firing one shot upon pulling the trigger and then firing a subsequent shot upon release of the trigger.
A trigger crank is a device that allows a semi-automatic firearm to fire at an increased rate. The trigger crank typically consists of a screw-tight clamp and crank assembly. The crank assembly is clamped onto the trigger guard of a semi-automatic firearm. The device is positioned in front of the trigger. When the crank is turned, tiny gears depress the trigger and cause the weapon to fire.
VanDerStok v. Garland is a federal court case brought by several plaintiffs from the firearms parts industry challenging the 2021 Bureau of Alcohol Tobacco and Firearms (ATF) regulatory revisions of the Gun Control Act definitions of firearm, firearm frame and receiver. On June 30, 2023, federal district court judge Reed O'Connor granted a motion for summary judgment against the ATF, vacating the receiver rule nationwide on the grounds that the agency had exceeded its statutory authority.
