An intermediate cartridge is a

rifle A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...

/ carbine cartridge that has significantly greater power than a

pistol A pistol is a type of handgun, characterised by a gun barrel, barrel with an integral chamber (firearms), chamber. The word "pistol" derives from the Middle French ''pistolet'' (), meaning a small gun or knife, and first appeared in the Englis ...

cartridge but still has a reduced

muzzle energy Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle (firearm), muzzle of a firearm. Without consideration of factors such as aerodynamics and gravity for the sake of comparison, muzzle energy is used as a rough indi ...

compared to fully powered cartridges (such as the .303 British, 7.62×54mmR, 7.65×53mm Mauser, 7.92×57mm Mauser, 7.7×58mm Arisaka, , or 7.62×51mm NATO), and therefore is regarded as being "intermediate" between traditional rifle and handgun cartridges. As their

recoil Recoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, for according to Newton's third law the force requ ...

is significantly reduced compared to full-power cartridges, fully automatic rifles firing intermediate cartridges are relatively easy to control. However, even though they are less powerful than a traditional full-power cartridge, the

external ballistics External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a projectile in flight. The projectile may be powered or un-powered, guided or unguided, spin or fin stabilized, flying through an atmosphere or ...

are still sufficient for an

effective range Effective range is a term with several definitions depending upon context. Distance Effective range may describe a distance between two points where one point is subject to an energy release at the other point. The source, receiver, and conditio ...

of , which covers most typical infantry engagement situations in modern warfare. This allowed for the development of the

assault rifle An assault rifle is a select fire rifle that uses an intermediate cartridge, intermediate-rifle cartridge and a Magazine (firearms), detachable magazine.C. Taylor, ''The Fighting Rifle: A Complete Study of the Rifle in Combat'', F.A. Moyer '' ...

, a type of versatile selective fire

small arms A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originate ...

that is lighter and more compact than traditional

battle rifle A battle rifle is a service rifle chambered to fire a fully powered cartridge. The term "battle rifle" is a retronym created largely out of a need to differentiate automatic rifles chambered for fully powered cartridges from automatic rifles cha ...

s that fire full-power cartridges. The first known early intermediate cartridge to see service was the 10.4x38mmR Swiss used in the Vetterli rifle which gave it controllable handling and a ''then'' high-capacity magazine of 12 rounds. Predominant intermediate cartridges in mainstream circulation came around 50 years later and saw widespread use with the German 7.92×33mm Kurz used in the StG 44 and the .30 Carbine used in the American M2

select fire Select or SELECT may refer to: Arts, entertainment, and media * Select (album), ''Select'' (album), a 1982 album by Kim Wilde * Select (magazine), ''Select'' (magazine), a 1990–2001 British music magazine * ''MTV Select'', a 1996–2001 interac ...

carbine during the late years and closing days of World War II. With the data collected during World War II and the Korean War, the benefits of intermediate cartridges became apparent. This resulted in the development of "modern" cartridges such as the Soviet 7.62×39mm M43 (used in the SKS,

AK-47 The AK-47, officially known as the Avtomat Kalashnikova (; also known as the Kalashnikov or just AK), is an assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian small-arms designer Mikhail Kala ...

and AKM). Later an international tendency emerged towards relatively small-sized, lightweight, high-velocity Intermediate military service cartridges. Cartridges like the American 5.56×45mm M193 (1964; originally used in the M16), Soviet 5.45×39mm M74 (1974; used in the

AK-74 The AK-74 ( Russian: , tr. ''Avtomat Kalashnikova obraztsa 1974 goda'', lit. 'Kalashnikov assault rifle model 1974') is an assault rifle designed by small arms designer Mikhail Kalashnikov in 1974 as a successor to the AKM. While primarily ...

, which replaced the AKM), Belgian SS109 / 5.56×45mm NATO (1980; used in most AR-15 systems), and the Chinese

5.8×42mm The 5.8×42mm / DBP87 ( zh, p=Dàn, Bùqiāng, Pŭtōng, 87, s=弹，步枪，普通 87, ) is a military bottlenecked intermediate cartridge developed in the People's Republic of China. There is limited information on this cartridge, although ...

(1987; used in the

QBZ-95 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 law enforcement in China, la ...

) allow a soldier to carry more ammunition for the same weight compared to their larger and heavier predecessor cartridges, have favourable maximum point-blank range or "battle zero" characteristics and produce relatively low

bolt thrust Bolt thrust or breech pressure is a term used in internal ballistics and firearms (whether small arms or artillery) that describes the amount of rearward force exerted by the propellant gases on the Bolt (firearms), bolt or Breechblock, breech of a ...

and free recoil impulse, favouring lightweight arms design and automatic fire accuracy.

History

High power rounds

The late 19th and early 20th century saw the introduction of

smokeless powder Finnish smokeless powder Smokeless powder is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to black powder. Because of their similar use, both the original black powder formula ...

cartridges with small caliber jacketed spitzer bullets that extended the effective range of fire beyond the limitations of the open rifle sights. The Maxim gun, the world's first machine gun, was devised in 1885, and a year later, the Lebel Model 1886 rifle had the distinction of being the world's first smokeless powder

bolt-action rifle Bolt action is a type of manual firearm action that is operated by ''directly'' manipulating the turn-bolt via a bolt handle, most commonly placed on the right-hand side of the firearm (as most users are right-handed). The majority of b ...

. In the years leading up to World War I, the Lebel set an international example, and smokeless powder high power service cartridges and service rifles began to be produced by all the world's great powers. This included, but was not limited to, the German Gewehr 98, the British

Lee–Enfield The Lee–Enfield is a bolt-action, magazine-fed repeating rifle that served as the main firearm of the military forces of the British Empire and Commonwealth during the first half of the 20th century, and was the standard service rifle of th ...

, the Russian

Mosin–Nagant The Mosin–Nagant is a five-shot, Bolt action, bolt-action, Magazine (firearms), internal magazine–fed military rifle. Known officially as the 3-line rifle M1891, in Russia and the former Soviet Union as Mosin's rifle (, ISO 9: ) and inform ...

, and the American M1903 Springfield. These rifles weighed over , and they were longer than and as such were generally inappropriate for close combat. They fired cartridges and featured iron sight lines designed in an age when military doctrine expected rifle shots at ranges out to over for simultaneous fire at distant area targets like ranks of enemies, but typical combat ranges were much shorter, around , rarely exceeding .Military Small Arms Of The 20th Century, 7th Edition, 2000 by Ian V. Hogg & John S. Weeks, p.243

Introduction of semi- and full-auto weapons as service firearms

World War II revealed the demand for better fire density in infantry operations. To achieve this goal, both Allied and Axis countries rapidly developed and produced a number of semi-automatic service rifles, such as American

M1 Garand The M1 Garand or M1 rifleOfficially designated as U.S. rifle, caliber .30, M1, later simply called Rifle, Caliber .30, M1, also called US Rifle, Cal. .30, M1 is a semi-automatic rifle that was the service rifle of the United States Army, U.S. ...

, Soviet SVT-40 and the German Gewehr 43. Compared to their bolt-action predecessors, these weapons provided a considerably higher effective fire rate. In 1951, the US military published a study on the M1 Garand's fire rate: a trained soldier averaged 40–50 accurate shots per minute at a range of . "At ranges over , a battlefield target is hard for the average rifleman to hit. Therefore, is considered the maximum effective range, even though the rifle is accurate at much greater ranges".U. S. RIFLE, CALIBER .30, M1, DEPARTMENTS OF THE ARMY AND THE AIR FORCE, October 1951
/ref> Simultaneously, armies of both sides had put

submachine gun A submachine gun (SMG) is a magazine (firearms), magazine-fed automatic firearm, automatic carbine designed to fire handgun cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun, to descri ...

s to extensive use. Soviet

PPSh-41 The PPSh-41 () is a selective-fire, open-bolt, blowback submachine gun that fires the 7.62×25mm Tokarev round. It was designed by Georgy Shpagin of the Soviet Union to be a cheaper and simplified alternative to the PPD-40. The PPSh-41 saw ...

and PPS-43, US Thompson, British Sten and the German MP-40 had an even higher fire rate (and thus higher fire density) compared to larger-caliber semi auto rifles, but their effective range was considerably shorter: e.g., vs for Thompson and M1 Garand, respectively. SMG, chambered in pistol calibers ( 7.62x25, 9x19 Parabellum and .45 ACP) lacked penetration provided by larger and faster rifle bullets. Seeking to combine the rapid fire capabilities of SMG and advantages of the rifle calibers, both Allied and Axis powers developed a range of early automatic rifles. The first automatic rifles to be adopted by the fighting armies were the German FG42 and Sturmgewehr 44.

Demand for lighter ammunition

Although efficient in the battlefield, early automatic rifles had a considerable drawback compared to both semi-automatic rifles and submachine guns. With a fire rate of 600-1000 rounds per minute, automatic rifles increased the amount of ammo a soldier had to carry. However, the ammo was much heavier (393 gr (25.4 g) for 7.62 x 51 round compared to 160 gr (10.4 g) for .45 ACP), effectively limiting the ammo load. Additionally, when fired in full automatic mode free recoil delivered by full-sized and full-powered cartridges became an issue, too. Though technically a full-powered cartridge, the first one to fulfil this requirement may have been the Japanese 6.5×50mm Arisaka used by the Russian

Fedorov Avtomat The Fedorov Avtomat (also anglicized as Federov, ) or FA is a select-fire infantry rifle and one of the world's first operational automatic rifles, designed by Vladimir Grigoryevich Fyodorov in 1915 and produced in the Russian Empire and later ...

rifle, used in limited numbers from 1915 to 1917 (the cartridge itself dates back to 1897). The Fedorov was arguably the first assault rifle. This led to a series of early attempts to produce a lower-powered round using existing calibers. Examples include the US .30 Carbine cartridge for the

M1 Carbine The M1 carbine (formally the United States carbine, caliber .30, M1) is a lightweight semi-automatic carbine chambered in the .30 carbine (7.62×33mm) cartridge that was issued to the U.S. military during World War II, the Korean War, and t ...

and the German 7.92×33mm Kurz, a shortened version of the standard 7.92×57mm Mauser round used in the StG-44, which is more commonly considered to be the first assault rifle. The Soviets developed a similar round, the 7.62×39mm, for the SKS but far better known as the round for the post-war

Post-war developments

These earlier examples were generally developed with the goal being ease of development and logistics, and lacked any rigorous study of their performance. In the immediate post-war era, the

British Army The British Army is the principal Army, land warfare force of the United Kingdom. the British Army comprises 73,847 regular full-time personnel, 4,127 Brigade of Gurkhas, Gurkhas, 25,742 Army Reserve (United Kingdom), volunteer reserve perso ...

began such a study with an eye to replacing its pre-World War I .303 British. The .303 had been slated for replacement repeatedly, but a series of events kept it in service decades longer than expected. Their studies led to a new purpose-designed intermediate round, the .280 British, along with new weapons to fire it. The round attracted significant interest among other UK-oriented forces, but during

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

standardization effort the US was dead-set against any reduction in power. The British EM-2 bullpup rifle used an intermediate round, and was issued in limited numbers in the 1950s but the 7.62×51mm NATO was selected and it was removed from service. In practice, the 7.62×51mm NATO was found to be too powerful for select-fire weapons, as the British testing had warned. When the US entered the

Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...

it was armed with the semi-automatic M14 rifle while facing increasing numbers of full-automatic AK-47s. Demands for a select-fire weapon were constant but the Army was slow to respond. An ARPA program cleared the way for small numbers of a new and much smaller round, the .223 Remington, to be introduced to combat by

special forces Special forces or special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...

. Field reports were extremely favorable, leading to the introduction of the

M16 rifle The M16 (officially Rifle, Caliber 5.56 mm, M16) is a family of assault rifles adapted from the ArmaLite AR-15 rifle for the United States Armed Forces, United States military. The original M16 was a 5.56×45mm NATO, 5.56×45mm automatic ...

Universal service cartridge

Some militaries have considered the adoption of a 'universal service cartridge' – a replacement of small caliber, high-velocity intermediate cartridges and full-power cartridges with a cartridge at the larger end of the intermediate cartridge spectrum, well suited for both assault rifle and general-purpose machine gun use in the 6mm to 7mm caliber range, with external and terminal ballistic performance close or equal to the 7.62×51mm NATO and 7.62×54mmR full-power cartridges. The

US Army The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...

conducted testing of telescoped ammunition, polymer-cased ammunition, and

caseless ammunition Caseless ammunition (CL), or caseless cartridge, is a configuration of Cartridge (firearms), weapon-cartridge that eliminates the cartridge case that typically holds the Percussion cap, primer, propellant and projectile together as a unit. Instea ...

for future service cartridges. As of 2022, the candidate for

universal cartridge is the 6.8×51mm Common Cartridge, selected by the US Next Generation Squad Weapon Program. This cartridge has a muzzle energy even higher than 7.62×51mm NATO.

Characteristics

Typical intermediate cartridges have: * Bottlenecked, rimless cartridge * According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) and NATO EPVAT rulings the maximum service pressures range between P_max piezo pressure * Muzzle energies ranging between * Muzzle velocities ranging between * Relatively low O_ratios ranging between 2.87 and 7.99

List of intermediate cartridges

LE and Paramilitary

Cartridges issued to Law Enforcement and Paramilitary forces were or are chambered for. * .22 Spitfire cartridge of the Iver Johnson Spitfire * .221 Remington Fireball * .300 AAC Blackout * .375 SOCOM * .450 Bushmaster * .45 Raptor * .458 HAM'R * .458 SOCOM * .50 Beowulf *.500 Auto Max cartridge of the AR500 * 6.5mm Grendel * 7.62×37mm Musang *7.62×45mm Pindad cartridge of the Sabhara/Police V1-V2 * 8.6 mm Blackout * 9×39mm

Service cartridges

Service cartridges are cartridges the service rifles of armies were or are chambered for. * 5.45×39mm cartridge of the

assault rifle * 5.56×45mm NATO (.223 Remington) of the M16 assault rifle and M4 carbine *

cartridge of the

assault rifle * .30 Carbine (7.62×33mm) cartridge of the US M2 select fire carbine and M1 semi-automatic carbine * .345 Winchester Self-Loading of the Winchester-Burton M1917 automatic rifle * .351 Winchester Self-Loading of the Winchester Model 1907 semi-automatic rifle * 7.62×39mm cartridge of the

assault rifle and SKS semi-automatic carbine * 7.62×45mm cartridge of the vz. 52 semi-automatic rifle * 7.92×33mm Kurz cartridge of the StG 44 assault rifle

Premodern

Cartridges predating the modern era were chambered for. * 10.4x38mmR Swiss cartridge of the Vetterli rifle *10.4×47mmR cartridge of the M1870 Italian Vetterli *11x42mmR Albini-Comblain cartridge of the M1870 Belgian Comblain *11×50mmR Comblain cartridge of the M1870 Belgian Comblain *11mm Beaumont cartridge of the M1871 Beaumont rifle * 12.17×42mm RF *12x46mmR Musket Spain XPL *.43 Spanish Carbine *.45-75 WCF *.433 Egyptian * .50-70 Government *15.24х40R Krnka

Commercial

Cartridges privately sold on the civilian market. * Calhoon cartridges * .17 Mach IV * .17 Remington * .17 Remington Fireball * .20 VarTarg * 5 mm/35 SMc * .20 Tactical * .204 Ruger * 5.6×39mm * .22-250 Remington * .22 PPC * .219 Zipper * .224 Valkyrie * .222 Remington * .225 Winchester * 6mm BR * 6mm PPC * 6 mm XC * 6mm ARC * 6.5mm Creedmoor * 6mm AR * 6×45mm * .25-45 Sharps * .250-3000 Savage * 6.5×47mm Lapua * .277 Wolverine * 7mm BR Remington * 7×33mm Sako * 7.62×40mm Wilson Tactical * .30 Remington AR * .350 Legend * .35 Remington * .360 Buckhammer * .400 Legend * .401 Winchester Self-Loading

Prototype cartridges

Cartridges tested for standard issue or research were or are chambered for. * .351 Winchester Self-Loading cartridge for the Winchester Model 1907 * .345 Winchester Self-Loading cartridge for the Winchester Burton Machine Rifle * 4.5×26mm MKR one of the smallest assault rifle cartridges * 4.6×36mm *

4.85×49mm The 4.85×49mm is an experimental intermediate cartridge, intermediate Cartridge (firearms), firearm cartridge made by the United Kingdom for the Individual Weapon Project, which became the SA80 series of small arms. Design The 4.85×49mm cartr ...

cartridge of the experimental Enfield IW assault rifle *5.6x48mm Eiger cartridge of the W+F Stgw 70 and W+F Stgw 71 assault rifleshttps://schussfreude.ch/automatwaffen-ii-bewaffnung-und-ausruestung-der-schweizer-armee-seit-1817/ * 6×45mm SAW cartridge of the experimental Rodman Laboratories XM235 light machine gun, a project which terminated in the M249 * 6.45×48mm XPL Swiss cartridge of the experimental W+F Bern C42 assault rifle used in the WEIZE (Weiche Ziele, lit. "soft target") program * 6.5×39mm cartridge based on the 7.62×39mm of variants of the AR-15 and Zastava M70 assault rifles * 6.8mm Remington SPC (6.8×43mm) cartridge of the limited service LWRC M6 assault rifle * .280 British (7×43mm) cartridge of experimental weapons and the briefly in service EM-2 assault rifle *7.5×38mm Swiss trials Cartridge Stgw Patrone 47 *7.5×38mm chambered for the CEAM Modèle 1950 rifle and experimental French variant of StG 45(M) rifle *7.65×33mm Argentine variant of German 7.92×33mm cartridge for use in Argentine copy of German Sturmgewehr 44 assault rifle *7.65×35mm chambered in CEAM Modèle 1950 and experimental French variant of the StG 45(M) rifle *7.75×39mm GeCo the first intermediate round ever made, German experiment *7.92×41mm chambered for the CETME rifle * 12.7×55mm STs-130 subsonic cartridge of the limited service ShAK-12 assault/battle rifle

References

External links

Assault Rifles and their Ammunition: History and Perspectives
{{DEFAULTSORT:Intermediate Cartridges Cartridge families