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. [1] 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 (Trigger Mechanism Housing in some cases) that holds the fire control group, pistol grip, selector, stock etc. [2]
The receiver is often made of forged, machined, or stamped steel or aluminium. Apart from these traditional materials, modern techniques have introduced polymer and sintered metal powder receivers to the market. [3]
A barrel may typically be affixed to a firearm receiver using barrel and receiver action threads or similar methods.
For the purposes of United States law, the receiver or frame is legally the firearm, [4] and as such it is the controlled part. The definition of which assembly is the legal receiver varies from firearm to firearm, under US law. Generally, the law requires licensed manufacturers and importers to mark the designated receiver with a serial number, the manufacturer or importer, the model and caliber. Makers of receivers are restricted by International Traffic in Arms Regulations. Thus, in the case of a firearm that has multiple receiver parts, such as the AR-15, which has an upper and a lower receiver, the legally controlled part is the one that is serialized. [5]
For the AR-15 rifle, the lower receiver assembly is legally considered the actual receiver, [5] although it is functionally a chassis that also houses the separate trigger group. In the FN-FAL rifle, it is the upper assembly that is serialized and legally considered the receiver. [6] [7] This has led to prosecutors dropping charges against illegal manufacturing of AR-type firearms to avoid court precedents establishing that neither the upper nor the lower receiver individually contain all the components to be legally classified as a firearm. [8]
"Unfinished receivers", also called "80 percent receivers" or "blanks", are partially completed receivers with no serial numbers. Purchasers must perform their own finishing work in order to make the receiver usable. The finishing of receivers for sale or distribution by unlicensed persons is against US law. [9] Because an unfinished 80% receiver is not a firearm, purchasers do not need to pass a background check. [9] The resulting firearm is known as a "ghost gun". [10]
During the Biden Administration, the ATF imposed regulations on the sale and marketing of unfinished receivers and kits containing them by revising the legal definition of receivers to include "a partially complete, disassembled, or nonfunctional frame or receiver, including a frame or receiver parts kit, that is designed to or may readily be completed, assembled, restored, or otherwise converted to function as a frame or receiver". (The term "receiver" was also redefined as referring to non-handgun firearms, while "frame" was redefined as referring to handguns exclusively.) The new definitions went into effect on August 24, 2022. [11] In the case VanDerStok v. Garland, filed on June 30, 2023, a federal court in Texas ruled that the new ATF regulations exceeded the agency's statutory authority, and struck them down. [12] However, on August 8, 2023, the Texas court's nationwide vacatur was temporarily placed on hold by the Supreme Court of the United States, leaving the new ATF regulations on unfinished receivers in place. [13]
A Zero Percent Receiver is a rectangular billet of metal of the appropriate size to make a finished receiver, but without any machining whatsoever. In California it is unlawful to possess an unserialized zero percent receiver, and it is unlawful to ship one into the state [14]
As of 2024 [update] , several designs and atleast two designs for 3D printable polymer lower unfinished receivers for the AR-15 have been released: the AR Lower V5 and the Charon. 3D printed designs may also be used to produce privately made firearms. [15]
Name | Date made public | Type | Process | Designer | Caliber |
---|---|---|---|---|---|
AR Lower V5 [16] | [16] | 2013, MarchReceiver: AR-15 rifle lower receiver [16] | FDM [17] | Defense Distributed [16] | .223 Rem/ 5.56x45 |
| |||||
Charon [18] [19] [20] | [18] | May 2013Receiver: AR-15 rifle lower receiver [18] [19] [20] | FDM [21] | WarFairy [19] [20] | .223 Rem/ 5.56x45 |
| |||||
WarFairy P-15 [18] | [18] | 2013, MayReceiver: AR-15 rifle lower receiver [16] | FDM [21] | WarFairy [19] [20] | .223 Rem/ 5.56x45 |
Hanuman AR-15 Bullpup [22] [23] | [22] [23] | 2014, MayReceiver: AR-15 rifle bullpup lower receiver [22] [23] | FDM w/ ABS | WarFairy [22] [23] | .223 Rem/ 5.56x45 |
| |||||
Ruger Charger [24] [25] [26] | [25] | 2014, JulyReceiver: Ruger 10/22 semi-automatic pistol [25] | FDM [27] | "Buck-o-Fama" (pseudonym) [25] | .22 Long Rifle |
A pistol version of the popular Ruger 10/22 rifle. [24] [25] | |||||
CM901 [28] | 2015, March | Receiver: AR-10 Receiver | FDM | Printed Firearm [29] | 7.62×51mm |
| |||||
Lopoint / Bigpoint [30] | 2019, November (v1); 2020, November (,40/.45); 2021, May (v2) | Frame: Hi-Point pistol frame | FDM | CTRLPew / Atmac / freeman1337 | 9×19mm Parabellum, .380 ACP, .40 S&W, .45 ACP |
Scz0rpion [31] | 2020, October | Receiver: CZ Scorpion Evo 3 receiver | FDM | Are We Cool Yet? | 9×19mm Parabellum |
3011 / 3011DS [34] | 2021, November; 2023, January (DS) | Receiver: 1911 based PDW | FDM | Deterrence Dispensed | .45 ACP, 9×19mm Parabellum, .22 TCM |
| |||||
3DPD10 [35] | 2023, April | Frame: Pistol frame | FDM | Avidity Arms | 9×19mm Parabellum |
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The receiver or frame is legally the firearm, and as such it is the part that requires a manufacturer's serial number and valid Possession and Acquisition Licence to acquire and own. In the case of a handgun frame or revolver frame, it is the part that requires a Restricted-class PAL (RPAL), and registration.
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.
A gunsmith is a person who repairs, modifies, designs, or builds guns. The occupation differs from an armorer, who usually replaces only worn parts in standard firearms. Gunsmiths do modifications and changes to a firearm that may require a very high level of craftsmanship, requiring the skills of a top-level machinist, a very skilled woodworker, and even an engineer. Gunsmiths perform factory-level repairs and renovations to restore well-used or deteriorated firearms to new condition. They may make alterations to adapt sporting guns to better fit the individual shooter that may require extensive modifications to the firearm's stocks and metal parts. Repairs and redesigns may require fabrication and fitting of unavailable parts and assemblies constructed by smiths themselves. Gunsmiths may also renew metal finishes or apply decorative carvings or engravings to guns. Many gun shops offer gunsmithing service on the premises.
A federal firearms license (FFL) is a license in the United States that enables an individual or a company to engage in a business pertaining to the manufacture or importation of firearms and ammunition, or the interstate and intrastate sale of firearms. Holding an FFL to engage in certain such activities has been a legal requirement within the United States since the enactment of the Gun Control Act of 1968. The FFL is issued by the Bureau of Alcohol, Tobacco, Firearms, and Explosives
The ArmaLite AR-7 Explorer is a semi-automatic firearm in .22 Long Rifle caliber, developed in 1959 from the AR-5 that was adopted by the U.S. Air Force as a pilot and aircrew survival weapon. The AR-7 was adopted and modified by the Israeli Air Force as an aircrew survival weapon in the 1980s.
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).
The Roberti–Roos Assault Weapons Control Act of 1989 (AWCA) is a California law that bans the ownership and transfer of over 50 specific brands and models of firearms, which were classified as assault weapons. Most were rifles, but some were pistols and shotguns. The law was amended in 1999 to classify assault weapons by features of the firearm. Firearms that were legally owned at the time the law was passed were grandfathered if they were registered with the California Department of Justice. The law was overturned in June 2021 in Miller v. Bonta; the ruling is stayed pending appeal.
Defense Distributed is an online, open-source hardware and software organization that develops digital schematics of firearms in CAD files, or "wiki weapons", that may be downloaded from the Internet and used in 3D printing or CNC milling applications. Among the organization's goals is to develop and freely publish firearms-related design schematics that can be downloaded and reproduced by anyone with a 3D printer or milling machine, facilitating the popular production of homemade firearms.
An AR-15–style rifle is a lightweight semi-automatic rifle based on or similar to the Colt AR-15 design. The Colt model removed the selective fire feature of its predecessor, the original ArmaLite AR-15, which is a scaled-down derivative of the AR-10 design. It is closely related to the military M16 rifle.
The AAC Honey Badger is an AR-pattern personal defense weapon, designed primarily for use in a suppressed configuration. It is chambered in .300 AAC Blackout and was originally produced by Advanced Armament Corporation (AAC). The weapon is named after the honey badger.
The DEFCAD Charon is an open source 3D-printable AR-15 lower receiver project that was partially inspired by the Fabrique Nationale P90. It began as a design exercise by a DEFCAD user to explore FDM additive manufacturing technology as a means of integrating the P90's ergonomics into a stock for the AR-15, resulting in the WarFairy P-15 stock set.
A 3D printed firearm is a firearm that is partially or primarily produced with a 3D printer. While plastic printed firearms are associated with improvised firearms, or the politics of gun control, digitally-produced metal firearms are more associated with commercial manufacturing or experiments in traditional firearms design.
The Hanuman AR-15 Bullpup which was made public in May 2014 is a prototype AR-15 rifle Bullpup created by WarFairy
The SIG MCX is a family of firearms designed and manufactured by SIG Sauer, produced in both selective fire and semi-automatic only models, and features a short-stroke gas piston system, which is inherited from the earlier SIG MPX submachine gun. The MCX is available in rifle, carbine, short-barreled rifle, and pistol configurations.
A parts kit is a collection of weapon parts that, according to the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF), "is designed to or may be readily be assembled, completed, converted, or restored to expel a projectile by the action of an explosive." As an example, the kit may not include a receiver or include an incomplete receiver. Under current U.S. law, kits that include finished receivers must be serialized and their buyers must receive a background check, but kits that include "unfinished" receivers are totally unregulated for purchase.
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.
The FGC-9 is a 3D-printable, semi-automatic, pistol-caliber carbine. The firearm was first designed and manufactured between 2018 and 2020 by Jacob Duygu, a Kurdish German gun designer known by the pseudonym "JStark1809". In April 2021, a "MkII" revision was released. As of 2024, the FGC-9 is "by far" the world's most common 3-D printed gun, used by insurgents, militia members, terrorists, and drug traffickers in "at least 15 countries". The gun's most prominent promoter and co-designer is "Ivan The Troll," a man identified as John Elik in legal documents.
Polymer80, Inc. is an American manufacturer of parts kits containing firearm parts including unfinished receivers used for making privately made firearms. The company was founded in 2013 by Loran Kelley Jr. and David Borges and is headquartered in Dayton, Nevada. Polymer80 has received press coverage because of the use of their products in crimes involving so-called "ghost guns", which in specific cases has resulted in lawsuits being brought against the company.
The Urutau is a physible, 3D-printable, semi-automatic, bullpup, pistol-caliber carbine. The firearm was designed and manufactured between 2021 and 2024 by a gun designer known by the pseudonyms "Joseph The Parrot" and "Zé Carioca."
Firearm frame or receiver. That part of a firearm which provides housing for the hammer, bolt or breechblock, and firing mechanism, and which is usually threaded at its forward portion to receive the barrel.