20 mm caliber is a specific size of popular autocannon ammunition. It is typically used to distinguish smaller-caliber weapons, commonly called "guns", from larger-caliber "cannons" (e.g. machine gun vs. autocannon). All 20 mm cartridges have an outside projectile (bullet) diameter and barrel bore diameter of 0.787 inches (20.0 mm). These projectiles are typically 75 to 127 mm (3–5 in) long, cartridge cases are typically 75 to 152 mm (3–6 in) long, and most are shells, with an explosive payload and detonating fuze.
The usual nomenclature of ammunition indicates the diameter of projectile and the length of the cartridge that holds it; for example, 20×102 mm is a 20 mm projectile in a 102 mm long case.
Though this designation is often assumed to be unique, this is not always the case, e.g. there are three different 20×110 mm types which are not compatible. These may be distinguished in that some cartridge designations may include additional letters or names as a suffix, e.g. the various different types of 20×110 mm might be distinguished as 20×110 mm Hispano, 20×110 mm RB and 20×110 mm USN.
Common suffixes
B e.g. 20×138B: the cartridge has a belt which is used for headspacing, i.e. it helps ensure the correct positioning within the gun's chamber.
R e.g. 20×145R: a rimmed cartridge: the diameter of the rim forming the base is larger than that of the cartridge case itself.
RB e.g. Oerlikon 20×110RB: rebated rim, one where the rim is a smaller diameter than the case head allowing the extractor to follow it into the chamber, facilitating advanced-primer ignition, a recoil-moderating system.
^"Otomatik Orta Kalibre Top". 17 October 2022. Retrieved 17 October 2022.
^Williams, Anthony G (January 4, 2021). . Military Guns & Ammunition. Solo Publications. Archived from the original on March 30, 2022. Retrieved April 17, 2022.
External links
FAS: 20 mm Cannon Ammunition
ATK produced 20, 25 & 30 mm caliber ammunition
Rapid Fire: 20 mm Antitank Rifle Cartridges image
Rapid Fire: 20 mm Autocannon Cartridges WWII image 1
Rapid Fire: 20 mm Autocannon Cartridges WWII image 2
Rapid Fire: 20 mm Autocannon Cartridges Post-WWII image
January 10, 2023
caliber, 20mm, redirects, here, model, scale, list, scale, model, sizes, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sour. 20mm redirects here For the model scale see List of scale model sizes This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources 20 mm caliber news newspapers books scholar JSTOR April 2011 Learn how and when to remove this template message 20 mm caliber is a specific size of popular autocannon ammunition It is typically used to distinguish smaller caliber weapons commonly called guns from larger caliber cannons e g machine gun vs autocannon All 20 mm cartridges have an outside projectile bullet diameter and barrel bore diameter of 0 787 inches 20 0 mm These projectiles are typically 75 to 127 mm 3 5 in long cartridge cases are typically 75 to 152 mm 3 6 in long and most are shells with an explosive payload and detonating fuze Weapons using this caliber range from anti materiel rifles and anti tank rifles to aircraft autocannons and anti aircraft guns Contents 1 Usage 2 Types of ammunition 3 20 mm weapons 3 1 Current weapons 3 2 Historical weapons 4 Naming conventions 4 1 Common suffixes 5 See also 6 References 7 External linksUsage Edit A 20 102 mm round second from left with 50 BMG rounds golf ball and a stick of 168 pin SDRAM computer memory Twenty millimeter caliber weapons are generally not used to target individual soldiers but have targets such as vehicles buildings or aircraft Types of ammunition EditHigh explosive HE High explosive incendiary HEI Armor piercing AP Semi armor piercing high explosive incendiary SAPHEI Armor piercing discarding sabot APDS High explosive fragmentation tracer HEF T High explosive high capacity HE M Penetrator with enhanced lateral effect PELE Target practice inert projectile i e PGU 27A B 1 Used for training TP Target practice tracer inert projectile with tracer material in base for visual trajectory tracking i e PGU 30A B TP T 20 mm weapons EditEach weapon is listed with its cartridge type appended Current weapons Edit Weapon Country of origin Cartridge NotesNeopup PAW 20 South Africa 20 42 mmDenel NTW 20 South Africa 20 82 mm MauserDenel Vektor GA 1 South AfricaVidhwansak IndiaAnzio 20 mm rifle United States 20 102 mmM61 Vulcan United StatesM197 electric cannon United StatesM39 cannon United StatesGIAT M621 FranceZVI PL 20 Plamen Czech RepublicNexter Narwhal 20A France Based on the M621Sahi 20 102 Turkey 2 Metallic RT 20 Croatia 20 110 mm HispanoYugoimport SDPR M71 08 Serbia Single barrel development of Zastava M55Oerlikon KAA KAB Switzerland 20 128 mm Formerly known as Oerlikon 204GK 5TGMeroka CIWS SpainOerlikon KAD Switzerland 20 139 mm Formerly known as Hispano Suiza HS 820GIAT M693 20 mm modele F2 FranceRheinmetall Rh 202 GermanyDenel Land Systems GI 2 South AfricaNexter Narwhal 20B France Based on the 20 mm F2Historical weapons Edit Weapon Country of origin Cartridge NotesBecker Type M2 20 mm cannon German Empire 20 70 mm RBOerlikon FF Switzerland 20 72 mm RBType 99 cannon model 1 JapanIkaria Werke Berlin MG FF M cannon Nazi Germany 20 80 mm RBMauser MG 151 20 Nazi Germany 20 82 mmHo 5 cannon Japanese Empire 20 94 mmBerezin B 20 Soviet Union 20 99 mm R 3 ShVAK Soviet UnionHelenius RK 20 APH Finland Derivative of the Helenius RK 97 12 7 mm anti materiel rifleGhan Krnka fortress rifle Russian Empire 20 3 95 mm R Bullet diameter 21 mmType 99 cannon model 2 Japanese Empire 20 101 mm RBSolothurn S 18 100 Switzerland 20 105 mm BBofors m 45 Sweden 20 110 mmBofors m 49 SwedenHispano Suiza HS 404 and derivatives SwitzerlandOerlikon F FFL Switzerland 20 110 mm RBPolsten Poland 20 110 mm RBColt Mk 12 cannon United States 20 110 mm USN Advanced derivative of the HS 404Madsen 20 mm anti aircraft cannon Denmark 20 120 mmType 97 automatic cannon Japanese Empire 20 124 mmMauser MG 213 Nazi Germany 20 135 mmSolothurn S 18 1000 anti tank rifle Switzerland 20 138 mm BSolothurn S 18 1100 anti tank rifle SwitzerlandST 5 20 mm AA gun SwitzerlandFlaK 30 and FlaK 38 single barrel AA Nazi Germany Forerunner of Hispano Suiza HS 820 s post war 20 139 mm roundFlakvierling quadruple barrel AA Nazi GermanyMG C 30L aircraft gun Nazi GermanyRheinmetall KwK 30 and KwK 38 Nazi GermanyCannone Mitragliera da 20 65 modello 35 Breda Kingdom of ItalyCannone Mitragliera da 20 77 Scotti Kingdom of ItalyLahti L 39 anti tank rifle Finland Solothurn LongLahti L 40 anti aircraft gun FinlandNkm wz 38 FK anti tank vehicle mounted gun Poland Designated heaviest machine gun or Najciezszy karabin maszynowy Nkm AA AT actually an autocannon Type 98 20 mm AA machine cannon and Type 4 20 mm twin AA machine cannon Japan 20 142 mmBofors m 40 Sweden 20 145 mm RPansarvarnsgevar m 42 Sweden 20 180 mm R Recoilless rifleNaming conventions EditThe usual nomenclature of ammunition indicates the diameter of projectile and the length of the cartridge that holds it for example 20 102 mm is a 20 mm projectile in a 102 mm long case Though this designation is often assumed to be unique this is not always the case e g there are three different 20 110 mm types which are not compatible These may be distinguished in that some cartridge designations may include additional letters or names as a suffix e g the various different types of 20 110 mm might be distinguished as 20 110 mm Hispano 20 110 mm RB and 20 110 mm USN Common suffixes Edit B e g 20 138B the cartridge has a belt which is used for headspacing i e it helps ensure the correct positioning within the gun s chamber R e g 20 145R a rimmed cartridge the diameter of the rim forming the base is larger than that of the cartridge case itself RB e g Oerlikon 20 110RB rebated rim one where the rim is a smaller diameter than the case head allowing the extractor to follow it into the chamber facilitating advanced primer ignition a recoil moderating system See also Edit 50 BMG 950 JDJ 14 5 114 mm 20 110mm USN 23 mm caliber 23 115 mm 23 152 mm 25 mm caliber 30 mm caliberReferences Edit PGU 27A B TP PGU 28A B SAPHEI PGU 30A B TP T Otomatik Orta Kalibre Top 17 October 2022 Retrieved 17 October 2022 Williams Anthony G January 4 2021 Ammunition Data Tables 20 mm Calibre Cartridges Military Guns amp Ammunition Solo Publications Archived from the original on March 30 2022 Retrieved April 17 2022 External links EditFAS 20 mm Cannon Ammunition ATK produced 20 25 amp 30 mm caliber ammunition Rapid Fire 20 mm Cartridge Data Table Rapid Fire 20 mm Antitank Rifle Cartridges image Rapid Fire 20 mm Autocannon Cartridges WWII image 1 Rapid Fire 20 mm Autocannon Cartridges WWII image 2 Rapid Fire 20 mm Autocannon Cartridges Post WWII image Retrieved from https en wikipedia org w index php title 20 mm caliber amp oldid 1131425438, wikipedia, wiki, book, books, library,