A homemade pistol, confiscated by the Swedish Police. Given to the Museum of Vänersborg in 1985

Improvised firearms (sometimes called zip guns, pipe guns, or slam guns) are firearms manufactured other than by a firearms manufacturer or a gunsmith, and are typically constructed by adapting existing materials to the purpose. They range in quality from crude weapons that are as much a danger to the user as the target to high-quality arms produced by cottage industries using salvaged and repurposed materials.[1][2][3]

Improvised firearms may be used as tools by criminals and insurgents and are sometimes associated with such groups;[4][5] other uses include self-defense in lawless areas and hunting game in poor rural areas.[6]


This section is missing information about electric ignition; other improvised ammo setups. Please expand the section to include this information. Further details may exist on the talk page. (July 2022)

Zip guns

Zip guns are generally crude homemade firearms consisting of a barrel, breechblock and a firing mechanism. For small, low-pressure cartridges, like the common .22 caliber rimfire cartridges, even very thin-walled tubing works as a barrel, strapped to a block of wood for a handle. A rubber band powers the firing pin, which the shooter pulls back and releases to fire. Such weak tubing results in a firearm that can be as dangerous to the shooter as the target; the poorly fitting smoothbore barrel provides little accuracy and is liable to burst upon firing.[1] The better designs use heavier pipes and spring loaded trigger mechanisms. Larger zip guns, such as homemade shotguns called tumbera (Argentina), bakakuk[7] (Malaysia), or sumpak[8] (Philippines) are also made of improvised materials like nails, steel pipes, wooden pieces, bits of string, etc.

Pen guns

Homemade pen guns (Museum of the History of Donetsk militsiya)
Homemade pen guns (Museum of the History of Donetsk militsiya)

Pen guns are zip gun-like firearms that resemble ink pens.[9][10] They generally are of small caliber (e.g., .22 LR, .25 ACP, .32 ACP, etc.)[11][12][13] and are single shot.[12][14] Early examples of pen guns were pinfired, but modern designs are rimfire or centerfire.[9] Some pen guns are not designed to fire regular cartridges, but rather blank cartridges, signal flares, or tear gas cartridges.[9][15]

In the United States, pen guns that fire bullets or shot cartridges do not require a reconfiguration to fire, (e.g., folding to the shape of a pistol) and are federally regulated as an Any Other Weapon (Title II). They require registration under the National Firearms Act and a tax in the amount of $200 to manufacture or $5 to transfer is levied.[15][16]

Pipe guns

Pipe guns were first seen in the Philippines during World War II.[17] The "paliuntod" is a type of improvised shotgun commonly used by guerrillas and the joint American and Filipino soldiers who remained behind after Douglas MacArthur's withdrawal. Made of two pieces of pipe that fit snugly together, the "paliuntod" were simple, single shot guns. These pipe guns are still in use by both criminals and rebels in the Philippines.[18][19]

In 1946, pipe guns were patented in the United States by Iliff D. "Rich" Richardson, who fought with the Filipino insurgents during the Japanese occupation.[17][20] Made by "Richardson Industries" as the "Model R5 Philippine Guerrilla Gun", these 12 gauge shotguns sold for $7 at the time.[17]

Improvised versions are made by using two pipes and an end-cap; they usually fire shotgun shells. To fire the gun, the user inserts a shotgun shell into the smaller diameter pipe, places the smaller pipe into the larger diameter pipe, and forcefully slides it back until the shell's primer makes contact with a fixed firing pin located inside the end-cap.[4][5] Other improved versions use improvised detachable magazines.[21]

A homemade pipe shotgun that shoots .410 shotgun shells.

Repurposed or conversions

Flare guns have also been converted to firearms. This may be accomplished by replacing the (often plastic) barrel of the flare gun with a metal pipe strong enough to chamber a shotgun shell, or by inserting a smaller-bore barrel into the existing barrel (such as with a caliber conversion sleeve) to chamber a firearm cartridge, such as a .22 Long Rifle.[22][23]

A zip gun constructed from a toy cap gun. The gun is capable of shooting a .22 caliber round

More advanced improvised guns can use parts from other gun-like products. One example is the cap gun. A cap gun can be disassembled, and a barrel added, turning the toy gun into a real one. A firing pin can then be added to the hammer, to concentrate the force onto the primer of the cartridge. If the cap gun has a strong enough hammer spring, the existing trigger mechanism can be used as-is; otherwise, rubber bands may be added to increase the power of the hammer.[24]

Air guns have also been modified to convert them to firearms. The Brocock Air Cartridge System, for example, uses a self-contained "cartridge" roughly the size of a .38 Special cartridge, which contains an air reservoir, valve, and a .22 caliber (5.5 mm) pellet. Examples of BACS airguns converted to firearms, either by drilling the barrel out to fire a .38 Special cartridge or by altering the cylinder to accept .22 caliber cartridges, have been used in a number of crimes. Blank-firing guns can also be converted by adding a barrel, although the low-quality alloys used for cheaper blank-firing guns may break with the pressures and stresses of a real bullet being fired.[25]

Cryptic firearms

See also: Title II weapons § Any other weapon

Some more complex improvised firearms are not only well-built, but also use mimicry as camouflage, taking the appearance of other items. Improvised firearms in the form of flashlights, cellular telephones, canes and large bolts have all been seized by law enforcement officials.[citation needed] Most of these are .22 caliber rimfires, but flashlight guns have been found ranging from small models firing .22 Long Rifle to larger ones chambered for .410 bore shotgun shells.[26][27]

While most improvised firearms are single-shot, multiple-shot versions are also encountered. The simplest multi-shot zip guns are derringer-like, and consist of a number of single-shot zip guns attached together. The pepper-box design is also used in homemade guns because it is relatively easy to make out of a bundle of pipes or a steel cylinder. In late 2000, British police encountered a four-shot .22 LR zip gun disguised as a mobile phone, where different keys on the keypad fire different barrels. Because of this discovery, mobile phones are now X-rayed by airport screeners worldwide. Authorities believe they were manufactured in Croatia, and they still turned up in Europe as late as 2004, according to a report by Time magazine.[28][29]

Submachine guns

Homemade submachine guns are often made by copying existing designs, or by adapting simple, open-bolt actions and leveraging commonly available hardware store parts.[2][30]

The Błyskawica (Polish for lightning) was a submachine gun produced by the Armia Krajowa, or Home Army, a Polish resistance movement fighting the Germans in occupied Poland. Together with a Polish version of the Sten sub-machine gun, with which it shares some design elements, it was the only weapon mass-produced covertly in occupied Europe during World War II.

The Bechowiec (also known as the Bechowiec-1) was a Polish World War II submachine gun developed and produced by the underground Bataliony Chłopskie (BCh, Peasants' Battalions) resistance organisation. It was designed in 1943 by Henryk Strąpoć and was produced in underground facilities in the area of Ostrowiec Świętokrzyski. Its name was coined after the Bataliony Chłopskie organization members who were informally called bechowiec (plural: bechowcy).

The Borz (Борз, Chechen for "wolf") submachine gun is one of a number of improvised firearms produced in Chechnya. It was produced in small numbers from 1992 to 1999. It was used primarily by Chechen separatists. It is named after the Borz (wolf) because of its position as Chechnya's national animal.

The Carlo (also referred to as Carl Gustav) is a submachine gun manufactured by small workshops in the West Bank. The design has been inspired by the Swedish Carl Gustav m/45 and its Egyptian Port Said variant; however, the similarity is often only passing. Produced in several locations and often with second-hand gun parts, the specifications are not uniform. Typically the weapon is automatic. Often chambered for 9mm Parabellum pistol cartridges, variants for .22 LR, .32 ACP, 9mm Makarov, and 5.56 NATO are also produced. The weapon itself is cheap to manufacture but is inaccurate and prone to jamming and misfires.[31][32][33][34][35][36]


The FP-45 Liberator and the Deer gun were crude zip gun-like single-shot pistols or derringers manufactured by the United States government for use by resistance forces in occupied territories, during World War II and the Vietnam War, respectively.

FP-45 Liberator (Zip Gun)

The FP-45 was designed to be cheaply and quickly mass-produced. It had just 23 largely stamped and turned steel parts that were cheap and easy to manufacture. It fired the .45 ACP pistol cartridge from an unrifled barrel and five rounds of .45 ACP ammunition could be stored in the pistol grip. Due to this limitation, it was intended for short range use, 1–4 yards (0.91–3.66 m). Its maximum effective range was only about 25 ft (7.6 m). At longer range, the bullet would begin to tumble and stray off course. The original delivered cost for the FP-45 was USD$2.10/unit, lending it the nickname "Woolworth pistol".[37]

Deer gun (or Zip Gun)

The Deer gun fired the 9mm Parabellum pistol cartridge. It was made of cast aluminium, with the receiver formed into a cylinder at the top of the weapon. The striker protruded from the rear of the receiver and was cocked in order to fire, and a plastic clip was placed there to prevent an accidental discharge, as the Deer gun had no mechanical safety. The grip had raised checkering, was hollow, and had space for three 9mm Parabellum rounds and a rod for clearing the barrel of spent cases. The Deer gun lacked any marking identifying manufacturer or user, in order to prevent tracing of the weapons, and all were delivered in unmarked polystyrene boxes with three 9mm Parabellum rounds and a series of pictures depicting the operation of the gun. A groove ran down a ramp on top for sighting. The barrel unscrewed for loading and removing the empty casing. A cocking knob was pulled until cocked. The aluminium trigger had no trigger guard.

3D printed firearms

The 'Liberator' is a 3D-printable single shot handgun, the first such printable firearm design made widely available online

Main article: 3D printed firearms

In 2012, the U.S.-based group Defense Distributed disclosed plans to design a working plastic gun that could be downloaded and reproduced by anybody with a 3D printer.[38][39] The Liberator is a physible, 3D-printable single shot handgun, the first such printable firearm design made widely available online.[40][41][42] The open source firm Defense Distributed designed the gun and released the plans on the Internet on May 6, 2013. The plans were downloaded over 100,000 times in the two days before the United States Department of State demanded that Defense Distributed retract the plans, deeming them a violation of the Arms Export Control Act.[43][44][45] In 2015, Defense Distributed founder Cody Wilson sued the United States government on free speech grounds and in 2018 the Department of Justice settled, acknowledging Wilson's right to publish instructions for the production of 3D-printed firearms.[46][47]

The Solid Concepts 3D printed 1911 pistol

Defense Distributed has also designed a 3D printable AR-15 type rifle lower receiver (capable of lasting more than 650 rounds) and a variety of magazines, including for the AK-47.[48] In 2013 a California company, Solid Concepts, demonstrated a 3D printed version of an M1911 pistol made of metal, using an industrial 3D printer.[49]

Around the world

In the United States, creating an improvised firearm for personal use does not require licensure, registration, a background check, or the stamping of a serial number, but the firearm created must be detectable by a metal detector per federal law.[50][51] California, however, passed a law in 2016 that requires anyone planning to build a homemade gun to obtain a serial number from the state (de facto registration) and pass a background check.[52] However, such firearms are often illegal in other jurisdictions and are commonly associated with gangs, where they may be used to facilitate violent crime, such as homicide.[1] In other cases, they may be used for other criminal activities not necessarily related to violent crime, such as illegal hunting of game.[6] Improvised firearms are most commonly encountered in regions with restrictive gun control laws.[citation needed] While popular in the United States in the 1950s, the "zip gun" has become less common.

Copies of British Martini and Snider firearms built in the Khyber region

A Khyber Pass copy is a firearm manufactured by cottage gunsmiths in the Khyber Pass region between Pakistan and Afghanistan. The area has long had a reputation for producing unlicensed, homemade copies of firearms using whatever materials are available – more often than not, railway rails, scrap motor vehicles, and other scrap metal. The quality of such firearms varies widely, ranging from as good as a factory-produced example to dangerously poor. Much of the gunsmithing is centered around the town of Darra Adam Khel.

In India, use of improvised country-made pistols is widespread, especially in the regions of Bihar and Purvanchal. The manufacture of these weapons has become a cottage industry, and the components are often manufactured from scrap material; examples include gun barrels fashioned from truck steering columns.

In areas like South Africa, improvised firearms are more common. In a study of Zululand District Municipality, South Africa, it was found that most improvised firearms were crude, 12-gauge shotguns, with a simple pull-and-release firing mechanism; like .22 rimfire cartridges, shotgun shells operate at low pressures, making them more suited for use in weak, improvised barrels.[25]

Even in the absence of commercially available ammunition, homemade black powder weapons can be used; such firearms were the subject of a crackdown in the People's Republic of China in 2008.[6] In many areas of Africa, such as Zimbabwe, poachers use improvised muskets and shotguns loaded with black powder stolen from mines.[53]

The city of Danao in Cebu, Philippines, has been making improvised firearms so long that the makers have become legitimate, and are manufacturing firearms for sale. The Danao makers manufacture .38 and .45 caliber revolvers, and semi-automatic copies of the Ingram MAC-10 and Intratec TEC-DC9.[2]

In 2004, an "underground weapons factory" was seized in Melbourne, Australia, yielding among other things a number of silenced copies of the Owen submachine gun, suspected to have been built for sale to local gangs involved in the illegal drug trade.[54]

Improvised firearms have also been used in Russia,[55][56] where they have been used in domestic homicides and terrorism.

Improvised firearms were used by the perpetrator of the Halle synagogue shooting; the homemade shotgun and "Luty" submachine gun repeatedly malfunctioned. The attacker, an antisemitic neo-Nazi terrorist, said while livestreaming the attack, "I have certainly managed to prove how absurd improvised weapons are."[57]

In Italy, Naples, Caivano, multiple illegal weapons by the notorious Camorra were found during a raid, among them was a homemade 22-caliber gun, 400 homemade shells (likely for another gun such as a lupara, another type of gun that is often homemade), a homemade suppressor, and a pen gun.[58]

In Japan, an improvised shotgun was used in the assassination of Shinzo Abe, former prime minister of Japan, on 8 July 2022.[59]

See also


  1. ^ a b c Harlan Ellison (1983). Memos from Purgatory. Ace Books. ISBN 0-441-52438-9., Chapter 4
  2. ^ a b c "Solon foresees export potential in local gun making industry". Sun Star. May 30, 2008. Archived from the original on August 29, 2008.((cite journal)): CS1 maint: bot: original URL status unknown (link)
  3. ^ Weisman, Steven R.; Times, Special To the New York (April 27, 1987). "India's Corner of Mystery: Bihar's Poor and Lawless". The New York Times. Archived from the original on November 10, 2012.
  4. ^ a b "April 1997 Questions And Answers". oldguns.net. Archived from the original on August 18, 2021.
  5. ^ a b "Defeating Spain in the Philippines: Handmade Filipino Gun". Smithsonian Institution. 2 August 2021. Archived from the original on January 3, 2023.
  6. ^ a b c "Gun briefing backfires in China". BBC News. 18 July 2008. Archived from the original on July 19, 2008. Retrieved January 5, 2010.
  7. ^ Jamili Nais (1996). Kinabalu Park and the Surrounding Indigenous Communities, Malaysia. South-South Cooperation Programme on Environmentally Sound Socio-Economic Development in the Humid Tropics. Retrieved 12 May 2013.
  8. ^ Small arms survey 2003: development denied. Oxford University Press. 2003. pp. 34–. ISBN 978-0-19-925175-9. Archived from the original on March 28, 2023. Retrieved 12 May 2013.
  9. ^ a b c John Minnery (1990). Fingertip Firepower: Pen Guns, Knives and Bombs. Paladin Press. pp. 33, 38. ISBN 0-87364-560-X.
  10. ^ Helias Doundoulaki (2008). I was Trained to be a Spy: A True Life Story. p. 65. ISBN 978-1425753795.
  11. ^ Wright, James D.; Rossi, Peter H.; Daly, Kathleen (1983). Under the Gun: Weapons, Crime and Violence in America. Hawthorne, NY: Aldine de Gruyter. ISBN 0202303063.
  12. ^ a b J. David Truby (1993). Zips, Pipes, And Pens: Arsenal Of Improvised Weapons. Paladin Press. p. 132. ISBN 0873647025.
  13. ^ "Instructions -- .25 ACP". Archived from the original on January 11, 2007. Retrieved 2014-02-18.
  14. ^ Stephen D. Carpenteri (October 2013). Gun Trader's Guide, Thirty-Fifth Edition: A Comprehensive, Fully Illustrated Guide to Modern Firearms with Current Market Values. Skyhorse Publishing. ISBN 978-1626360259.
  15. ^ a b "Identification of Firearms Within the Purview of the National Firearms Act". Archived from the original on March 5, 2023. Retrieved 2014-02-18.
  16. ^ "National Firearms Act Handbook". Archived from the original (PDF) on March 24, 2022. Retrieved 2014-02-18.
  17. ^ a b c Richardson Industries M5 Philippine guerrilla gun: A gun to get a gun Archived 2018-08-08 at the Wayback Machine Richardson Industries M5 Philippine guerrilla gun: A gun to get a gun 5/14/17 by Chris Eger
  18. ^ Niña Catherine Calleja (June 5, 2008). "3 suspected cattle rustlers killed in Cavite shootout". Inquirer.net.[permanent dead link]
  19. ^ Lizanilla J. Amarga (June 13, 2007). "Communists admit slay of 2 Cafgus, datus". Sun Star. Archived from the original on October 11, 2007.((cite journal)): CS1 maint: bot: original URL status unknown (link)
  20. ^ McCollum, Ian (2021-01-27). "Richardson Industries Slamfire Guerrilla Shotguns - Forgotten Weapons". www.youtube.com. Archived from the original on 2021-02-06. Retrieved 2021-02-07.((cite web)): CS1 maint: bot: original URL status unknown (link)
  21. ^ Gordon Dahle (November 10, 2023). "Homemade Slam-Fire Shotgun with Detachable Magazine". YouTube. Archived from the original on November 25, 2023.
  22. ^ US Department of Justice, District of Connecticut. "Project Safe Neighborhoods" (PDF). Archived from the original (PDF) on 2004-07-25.
  23. ^ UNITED STATES COURT OF APPEALS FOR THE FOURTH CIRCUIT. "UNITED STATES OF AMERICA v. BARRY WILLIAM DOWNER" (PDF). Archived from the original (PDF) on 2012-03-06. Retrieved 2008-08-14.
  24. ^ Bruce Barak Koffler (March 1970). "Zip Guns and Crude Conversions. When converted to a muzzleloader the cap's can be used as a percussion cap using powder extracted from cap's or scraped off match heads. Identifying Characteristics and Problems". The Journal of Criminal Law, Criminology, and Police Science. Northwestern University: 115–125.
  25. ^ a b Vincent J. M. Di Maio, M.D. (1999). Gunshot Wounds. CRC Press. ISBN 0-8493-8163-0.
  26. ^ "Crypto bolt gun". The Gun Zone. Archived from the original on 2008-06-13. Retrieved 2008-06-19.
  27. ^ Cops on alert for flashlight guns, BY ROCCO PARASCANDOLA, NEWSDAY STAFF WRITER, June 13, 2006
  28. ^ Zagorin, Adam. "Press M for Murder: Cell Phones That Kill". Time Magazine. Archived from the original on April 23, 2005.
  29. ^ "Video of cellphone gun firing". Archived from the original on 2007-10-04. Retrieved 2008-06-19.
  30. ^ P. A. Luty (1998). Expedient Homemade Firearms (PDF). Paladin Press. ISBN 978-0-87364-983-4. Archived from the original (PDF) on March 7, 2023. Retrieved 2016-04-04.
  31. ^ Meet the Carlo, Al-Monitor, Shlomi Eldar, 17 March 2016 Archived 2022-12-07 at the Wayback Machine
  32. ^ Homemade ‘Carlo’ gun becoming weapon of choice for Palestinian attackers, Newsweek, Jack Moore, 6 November 2016 Archived 2022-07-05 at the Wayback Machine
  33. ^ Say hello to ‘Carlo,’ the cheap, lethal go-to gun for terrorists, Times of Israel, Judah Ari Gross, 16 March 2016 Archived 2022-12-30 at the Wayback Machine
  34. ^ Homemade guns used in Palestinian attacks on Israelis, Guardian, 14 March 2016 Archived 2023-03-23 at the Wayback Machine
  35. ^ Cheap but lethal: the makeshift gun used by Palestinian shooters in Tel Aviv terror attack, Telegraph, Raf Sanchez, 10 June 2016 Archived 2023-03-23 at the Wayback Machine
  36. ^ The West Bank: Deadly DIY, The Economist, 7 April 2016 Archived 2022-09-01 at the Wayback Machine
  37. ^ Thompson, Leroy (3 May 2011). The Colt 1911 Pistol. Bloomsbury Publishing. p. 87. ISBN 978-1-84908-836-7.
  38. ^ Greenberg, Andy (August 23, 2012). "'Wiki Weapon Project' Aims To Create A Gun Anyone Can 3D-Print At Home". Forbes. Archived from the original on March 8, 2023. Retrieved August 27, 2012.
  39. ^ Poeter, Damon (August 24, 2012). "Could a 'Printable Gun' Change the World?". PC Magazine. Archived from the original on August 16, 2022. Retrieved August 27, 2012.
  40. ^ "US government orders removal of Defcad 3D-gun designs". BBC News. 10 May 2013. Archived from the original on October 31, 2022. Retrieved 13 May 2013.
  41. ^ Biggs, John. "What You Need To Know About The Liberator 3D-Printed Pistol". TechCrunch. Archived from the original on August 3, 2013. Retrieved 13 May 2013.
  42. ^ Hutchinson, Lee (3 May 2013). "The first entirely 3D-printed handgun is here". Ars Technica. Archived from the original on December 26, 2022. Retrieved 13 May 2013.
  43. ^ "Blueprints for 3-D printer gun pulled off website". www.statesman.com. Archived from the original on 2013-10-29. Retrieved 2013-11-10.
  44. ^ "Defense Distributed v. United States Department of State". harvardlawreview.org. Archived from the original on August 23, 2022. Retrieved 2017-10-01.
  45. ^ Greenberg, Andy. "3D-Printed Gun's Blueprints Downloaded 100,000 Times In Two Days (With Some Help From Kim Dotcom)". Forbes. Archived from the original on August 1, 2013. Retrieved 13 May 2013.
  46. ^ Kopel, David (2018-07-10). "US government drops prohibition on files for 3D printed arms". Reason.com. Archived from the original on 2018-07-13. Retrieved 2018-07-13.
  47. ^ Greenberg, Andy (2018-07-10). "A Landmark Legal Shift Opens Pandora's Box for DIY Guns". Wired.com. Archived from the original on 2018-07-10. Retrieved 2018-07-13.
  48. ^ Farivar, Cyrus (March 1, 2013). ""Download this gun": 3D-printed semi-automatic fires over 600 rounds". Ars Technica. Archived from the original on September 26, 2022. Retrieved February 5, 2015.
  49. ^ Gross, Doug (2013-11-09). "Texas company makes metal gun with 3-D printer". CNN. Archived from the original on September 27, 2022. Retrieved 9 November 2013.
  50. ^ "Does an individual need a license to make a firearm for personal use? | Bureau of Alcohol, Tobacco, Firearms and Explosives". www.atf.gov. Archived from the original on March 22, 2023. Retrieved 2017-10-01.
  51. ^ "Ghost Guns". Giffords Law Center. Archived from the original on March 15, 2023. Retrieved 25 May 2020.
  52. ^ "California governor signs bill to require registration of 'ghost guns'". Reuters. 2016-07-23. Archived from the original on August 30, 2022. Retrieved 2017-10-01.
  53. ^ McCollum, Ian (May 12, 2020). "Confiscated Homemade Poachers' Guns from Zimbabwe". youtube.com. Forgotten Weapons. Archived from the original on May 24, 2023. Retrieved May 24, 2023.((cite web)): CS1 maint: bot: original URL status unknown (link)
  54. ^ Brendan Nicholson, Daniel Ziffer (July 23, 2004). "Submachine-guns found in weapons factory". The Age. Melbourne. Archived from the original on April 4, 2022.
  55. ^ "Chechen Self-Made Weapons". English Russia. June 4, 2007. Archived from the original on June 27, 2022.
  56. ^ Stanley, Alessandra (January 17, 1995). "Seized Guns in Russia". The New York Times. Archived from the original on August 5, 2020. Retrieved May 5, 2010.
  57. ^ "Germany's Jewish leaders condemn police response to Halle attack". www.theguardian.com. 10 October 2019. Archived from the original on October 13, 2022.
  58. ^ "Camorra, arsenale nel Napoletano: Trovati kalashnikov e una "pen gun"" [Camorra Arsenal Discovered in the Neapolitan Region: Kalashnikovs and one pen gun]. 2 April 2017. Archived from the original on March 28, 2023.
  59. ^ Kim, Chang-Ran (June 7, 2022). "Shinzo Abe shot while making election speech in Japan". Reuters. Archived from the original on 8 July 2022. Retrieved 8 July 2022.

Further reading