View source for .303 British

{{Short description|British military rifle cartridge}}
{{Use dmy dates|date=August 2020}}

{{Infobox firearm cartridge
|name= .303 British 
|image=6.5x50mm Japanese with .303 British & .30-06.JPG | image_size = 300px
|caption= Left to right: .303 British, [[6.5×50mmSR Arisaka]] and [[.30-06 Springfield]] [[ballistic tip]] ammunition
|origin=[[United Kingdom of Great Britain and Ireland|United Kingdom]]
|type=[[Rifle]]
<!-- Service history -->
|service=1889–present
|used_by=United Kingdom and many other countries
|wars={{Plainlist|
* [[Second Boer War]]
* [[Boxer Rebellion]]
* [[World War I]]
* [[British Empire|Various Colonial conflicts]]
* [[Irish War of Independence]]
* [[Irish Civil War]]
* [[World War II]]
* [[Indonesian National Revolution]]
* [[Indo-Pakistani wars and conflicts|Indo-Pakistani Wars]]
* [[Greek Civil War]]
* [[Malayan Emergency]]
* [[First Indochina War|French Indochina War]]
* [[Korean War]]
* [[1948 Arab–Israeli War|Arab–Israeli War]]
* [[Suez Crisis]]
* [[Mau Mau Uprising]]
* [[Portuguese Colonial War]]
* [[Sino-Indian War]]
* [[Vietnam War]]
* [[Bangladesh Liberation War]]
* [[Soviet invasion of Afghanistan]]
* [[Nepalese Civil War]]
* [[War in Afghanistan (2001–present)|Afghanistan conflict]]
}}
<!-- Production history -->
|designer=
|design_date=
|manufacturer=
|production_date=1889–present
|number=
|variants=
<!-- Specifications -->
|parent=
|case_type=Rimmed, tapered, bottleneck
|is_SI_specs=yes
|bullet= 7.92
|land= 7.70
|neck=8.64
|shoulder=10.19
|base=11.68
|rim_dia=13.72
|rim_thick=1.63
|case_length=56.44
|length=78.11
|case_capacity=3.64
|rifling=254 mm (1-10 in)
|primer=Large rifle
|max_pressure=365.00
|pressure_method=C.I.P.
|max_pressure2=337.84
|pressure_method2=SAAMI
|max_cup=45,000
<!-- Ballistic performance -->
|velocity=
|energy=
<!-- Ballistic data, load 1 -->
|is_SI_ballistics=yes
|bw1=150
|btype1=SP
|vel1=844
|en1=3463
|bw2=174
|btype2=HPBT
|vel2=761
|en2=3265
|bw3=180
|btype3=SP
|vel3=783
|en3=3574
<!-- Ballistics data source -->
|test_barrel_length={{convert|24|inch|mm|abbr=on|sigfig=3}} <!-- precision justified by context implying high precision of original 24" figure -->
|balsrc= Accurate Powder<ref name="accurate">{{cite web
 |url=http://www.accuratepowder.com/data/PerCaliber2Guide/Rifle/Standarddata(Rifle)/311Cal(7.90mm)/303%20British%20pages%20282%20and%20283.pdf
 |title=.303 British
 |publisher=Accurate Powder
 |archive-url=https://web.archive.org/web/20081230110406/http://www.accuratepowder.com/data/PerCaliber2Guide/Rifle/Standarddata%28Rifle%29/311Cal%287.90mm%29/303%20British%20pages%20282%20and%20283.pdf
 |archive-date=30 December 2008
 |url-status=dead
 }}</ref>{{failed verification|reason=these values do not appear in source as given|date=April 2020}}
}}

The '''.303 British''' (designated as the '''303 British''' by the [[C.I.P.]]<ref name="ReferenceA">[https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/tabiical-en-page74.pdf C.I.P. TDCC datasheet 303 British]</ref> and [[SAAMI]]<ref name="ReferenceB">{{Cite web |url=http://www.saami.org/PubResources/CC_Drawings/Rifle/303%20British.pdf |title=SAAMI Drawing 303 British |access-date=25 December 2014 |archive-url=https://web.archive.org/web/20141225231536/http://www.saami.org/PubResources/CC_Drawings/Rifle/303%20British.pdf |archive-date=25 December 2014 |url-status=dead  }}</ref>) or '''7.7×56mmR''', is a {{convert|.303|in|mm|adj=on}} calibre [[Rim (firearms)#Rimmed|rimmed]] [[Tapering (firearms)|tapered]] bottleneck centerfire [[rifle]] [[Cartridge (firearms)|cartridge]]. The .303-inch bore diameter is measured between rifling [[Rifling|lands]] as is the common practice in [[Europe]] which follows the traditional black powder convention.

It was first manufactured in [[United Kingdom|Britain]] as a stop-gap [[black powder]] round put into service in December 1888 for the [[Lee–Metford]] rifle. From 1891 the cartridge used [[smokeless powder]] which had been the intention from the outset, but the decision on which smokeless powder to adopt had been delayed.<ref name="Cushman"/> It was the standard British and [[Commonwealth of Nations|Commonwealth]] military cartridge for rifles and machine guns from 1889 until it was replaced by the [[7.62×51mm NATO]]<ref name="ReferenceA"/> in the 1950s.

==Cartridge specifications==
The .303 British has a 3.64 [[litre|mL]] (56 [[grain (measure)|gr]] H<sub>2</sub>O) cartridge case capacity. The pronounced tapering exterior shape of the case was designed to promote reliable case feeding and extraction in [[bolt-action]] rifles and [[machine gun]]s alike, under challenging conditions.

[[File:.303 British.jpg|upright=1.8|center|thumb|.303 British maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).]]

Americans would define the shoulder angle at alpha/2 ≈ 17 degrees. The common [[rifling]] [[twist rate]] for this cartridge is {{convert|254|mm|in|abbr=on}}, 5 grooves, Ø lands = {{convert|7.70|mm|in|3}}, Ø grooves = {{convert|7.92|mm|in|3}}, land width = {{convert|2.12|mm|in|3}} and the [[Percussion cap|primer type]] is Berdan or Boxer (in large rifle size).

According to official rulings of the {{lang|fr|i=unset|[[Commission internationale permanente pour l'épreuve des armes à feu portatives]]}} (CIP), the .303 British can handle up to {{convert|3650.|bar|MPa psi}} P<sub>max</sub> piezo pressure.<ref>{{Cite web |title=CIP - 303 British|url=https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/tabiical-en-page74.pdf |access-date=2023-04-17 |website=bobp.cip-bobp.org}}</ref> In CIP-regulated countries every rifle cartridge combo has to be [[Proof (firearms)|proofed]] at 125% of this maximum CIP pressure to certify for sale to consumers.<ref name="ReferenceA"/>
This means that .303 British chambered arms in CIP-regulated countries are, {{as of|2023|lc=on}}, proof tested at {{convert|4562|bar|MPa psi}} PE piezo pressure.

The [[Sporting Arms and Ammunition Manufacturers' Institute]] (SAAMI) maximum average pressure (MAP) for this cartridge is {{cvt|49000|psi|MPa|sigfig=3}} piezo pressure (45,000 [[Copper units of pressure|CUP]]).<ref>[http://www.saami.org/specifications_and_information/specifications/Velocity_Pressure_CfR.pdf ANSI/SAAMI Velocity & Pressure Data: Centerfire Rifle] {{webarchive|url=https://web.archive.org/web/20130702015600/http://saami.org/specifications_and_information/specifications/Velocity_Pressure_CfR.pdf|date=2 July 2013}}</ref>

The measurement {{convert|.303|in|mm}} is the [[Real versus nominal value|nominal]] size of the bore measured between the lands which follows the older black powder nomenclature. Measured between the grooves, the nominal size of the bore is {{convert|.311|in|mm}}. Bores for many .303 [[military surplus]] rifles are often found ranging from around {{convert|.309|to(-)|.318|in|mm}}. Recommended bullet diameter for standard .303 British cartridges is {{convert|.312|in|mm}}.<ref>''Hornady Handbook of Cartridge Reloading, Rifle-Pistol'', Third Edition, Hornady Manufacturing Company, 1980, 1985, pp.&nbsp;253–254.</ref>

==Military use==
===History and development===
During a service life of over 70 years with the British Commonwealth armed forces, the .303-inch (7.7&nbsp;mm) cartridge in its ball pattern progressed through ten marks, eventually extending to about 26 variations.<ref name=Temple>Temple, B. A., ''Identification Manual of the .303 British Service Cartridge - No: 1 - BALL AMMUNITION'', Don Finlay (Printer 1986), p. 1. {{ISBN|0-9596677-2-5}}</ref>
The [[bolt thrust]] of the .303 British is relatively low compared to many other service rounds used in the early 20th century.{{Citation needed|date=February 2022}}

===Propellant===
The original .303 British service cartridge employed black powder as a propellant, and was adopted for the Lee–Metford rifle, which had [[rifling]] designed to lessen fouling from this propellant, which replaced the [[Martini-Henry]] rifle in 1888. Some Martini-Henrys were rebarrelled to use the new .303 as the "Martini–Metford".

The Lee–Metford was used as a trial platform by the British Committee on Explosives to experiment with many different smokeless powders then coming to market, including [[Ballistite]], [[Cordite]], and ''Rifleite''.<ref name="CHIS">Chisholm, Hugh, ''Encyclopædia Britannica'' (11th ed.), New York: The Encyclopædia Britannica Co., Vol. 23, (1911) p. 327</ref><ref name="SAN">Sanford, Percy Gerald, ''Nitro-explosives: a Practical treatise Concerning the Properties, Manufacture, and Analysis of Nitrated Substances'', London: Crosby Lockwood & Son (1896) pp. 166-173, 179</ref><ref name="WALK">Walke, Willoughby (Lt.), ''Lectures on Explosives: A Course of Lectures Prepared Especially as a Manual and Guide in the Laboratory of the U.S. Artillery School'', J. Wiley & Sons (1897) pp. 336-343</ref>  Ballistite was a stick-type smokeless powder composed of soluble [[nitrocellulose]] and [[nitroglycerine]].<ref name="WALK"/>  Cordite was a stick-type or 'chopped' smokeless gunpowder composed of nitroglycerine, [[gun-cotton]], and mineral jelly, while ''Rifleite'' was a true nitrocellulose powder, composed of soluble and insoluble nitrocellulose, [[phenyl amidazobense]], and volatiles similar to French smokeless powders.<ref name="SAN"/><ref name="WALK"/> Unlike Cordite, ''Rifleite'' was a flake powder, and contained no nitroglycerine.<ref name="WALK"/> Excessive wear of the shallow [[Metford rifling]] with all smokeless powders then available caused ordnance authorities to institute a new type of barrel rifling designed by the [[Royal Small Arms Factory]] at Enfield, to increase barrel life; the redesigned rifle introduced in 1895 as the [[Lee–Enfield]].<ref name="CHIS"/> After extensive testing, the Committee on Explosives selected Cordite for use in the Mark II .303 British service cartridge.<ref name="CHIS"/>

===Projectile===
The initial .303 Mark I and Mk II service cartridges used a {{convert|215|gr|g|adj=on}}, round-nosed, copper-nickel [[Full metal jacket (ammunition)|full metal jacket]]ed bullet with a [[lead]] core. After tests determined that the service bullet had too thin a jacket when used with cordite, the Mk II bullet was introduced, with a flat base and thicker copper-nickel jacket.<ref name="OMM">Ommundsen, Harcourt, and Robinson, Ernest H., ''Rifles and Ammunition Shooting'', New York: Funk & Wagnalls Co. (1915), pp. 117–119</ref>

===Mark II – Mark VI===
[[File:Mk VI .303 cartridge diagram Treatise on Ammunition 1915.jpg|thumb|left|upright|Longitudinal section of Mk VI ammunition 1904, showing the round nose bullet]]

The Mk II round-nosed bullet was found to be unsatisfactory when used in combat, particularly when compared to the "dum-dum" [[expanding bullet]] rounds issued in limited numbers in 1897 during the [[Chitral Expedition|Chitral]] and [[Tirah Campaign|Tirah]] expeditions of 1897–98 on the [[North-West Frontier Province (1901–1955)|North West Frontier]] of India.<ref name="OMM"/> This led to the 1898 introduction of the ''Cartridge S.A. ball .303 inch Cordite Mark III'', basically the original 215-grain (13.9 g) bullet with the jacketing cut back to expose the lead in the nose.<ref name="OMM"/><ref name=":0">{{Cite web|title=MISSILE INJURIES – Over a century of service: the .303 projectile and its wounding capabilities- a historical profile 1|url=https://jmvh.org/article/missile-injuries-over-a-century-of-service-the-303-projectile-and-its-wounding-capabilities-a-historical-profile-1/|access-date=2021-06-26|website=jmvh.org}}</ref> The Mk III load, however, was almost immediately withdrawn as a result of production issues leading to the introduction of the similar Mk IV [[hollow-point]] loading in February of the next year, which was put into mass production in Britain, Canada and New Zealand.<ref name=":0" /> Following the pivotal [[Battle of Omdurman]] of the [[Mahdist War]], Major Mathias of the [[Royal Army Medical Corps]] observed a young man who had been struck twice by Mark IV bullets:

{{blockquote|
He had a bullet wound of the left leg above the knee. The wound entrance was clean cut and very small. The projectile had struck the Femur, just above the internal condyle; the whole of the lower end of this bone, and upper end of the Tibia, were shattered to pieces, the knee joint being completely disorganised.

He had also been wounded in the right shoulder... The whole of the shoulder joint and scapular [sic] were shattered to pieces. In neither case was there any sign of a wound of exit.}}

The design of the Mk IV hollow-point bullet shifted bullet weight rearwards, improving stability and accuracy over the regular round-nose bullet.<ref name="OMM" /> These soft-nosed and hollow-point bullets, while effective against human targets, had a tendency to shed the outer metal jacket upon firing; the latter occasionally stuck in the bore, causing a dangerous obstruction.<ref name="OMM" /> This was addressed by the introduction of a revised Mk V loading later in October (controversially so, as by August the Hague Convention had already made the military implementation of such expanding bullets illegal) identical to the Mark IV round apart from the addition of 2% antimony to the lead core and an additional 1.3&nbsp;mm in length.<ref name=":0" />

The concern about expanding bullets was brought up at the [[Hague Conventions (1899 and 1907)|Hague Convention of 1899]] by Swiss and Dutch representatives. The Swiss were concerned about small arms ammunition that "increased suffering", and the Dutch focused on the British Mark III .303 loading in response to their treatment of [[Boer]] settlers in South Africa. The British and American defence was that they should not focus on specific bullet designs, like hollow-points, but instead on rounds that caused "superfluous injury". The parties in the end agreed to abstain from using expanding bullets.<ref name="OMM"/> With the use of expanding bullets against signatories of the convention deemed inhumane, the Mk III, Mk IV, and Mk V were withdrawn from active service. The remaining stocks (over 45 million rounds) were used for target practice. The Mark III and other expanding versions of the .303 were not issued during the [[Second Boer War]] (1899–1902). Boer guerrillas allegedly used expanding hunting ammunition against the British during the war, and New Zealand Commonwealth troops may have brought Mark III rounds with them privately after the Hague Convention without authorization.<ref>[http://sadefensejournal.com/wp/?p=2109 A Way Forward in Contemporary Understanding of the 1899 Hague Declaration on Expanding Bullets] - SAdefensejournal.com, 7 October 2013</ref>

To replace the Mk III, IV, and V, the ''Mark VI'' round was introduced in 1904, using a round nose bullet similar to the Mk II, but with a thinner jacket designed to produce some expansion, though this proved not to be the case.<ref>{{citation |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=21 March 1901 |url=https://api.parliament.uk/historic-hansard/commons/1901/mar/21/rejected-mark-iv-bullets#S4V0091P0-01962 |title=Rejected Mark IV. Bullets |volume= 91}}</ref><ref>{{cite web |url=http://www.thegunzone.com/dum-dum.html |title=Dum Dums |access-date=21 August 2008 |archive-url=https://web.archive.org/web/20080925190004/http://www.thegunzone.com/dum-dum.html |archive-date=25 September 2008 |url-status=dead  }}</ref>

===Mark VII===
[[File:Mk VII .303 cartridge diagram Treatise on Ammunition 1915.jpg|thumb|upright|right|Longitudinal section of Mk VII ammunition circa 1915, showing the "tail heavy" design]]

In 1898, [[Atelier de Construction de Puteaux]] (APX), with their "Balle D" design for the [[8×50mmR Lebel]] cartridge, revolutionised bullet design with the introduction of pointed "[[Spitzer (bullet)|spitzer]]" rounds. In addition to being pointed, the bullet was also much lighter in order to deliver a higher muzzle velocity. It was found that as velocity increased the bullets suddenly became much more deadly.<ref>[http://www.chuckhawks.com/8mm_lebel.htm 8x50R Lebel (8mm Lebel)]</ref>

In 1910, the British took the opportunity to replace their Mk VI cartridge with a more modern design. The ''Mark VII'' loading used a {{convert|174|gr|g|2|abbr=on}} pointed bullet with a flat-base. The .303 British Mark VII cartridge was loaded with {{convert|37|gr|g|2|abbr=on}} of Cordite MDT 5-2 (cordite MD pressed into tubes) and had a muzzle velocity of {{convert|2440|ft/s|m/s|0|abbr=on}} and a maximum range of approximately {{convert|3000|yd|m|abbr=on}}.<ref name="Cushman" >{{cite web
  |url=http://www.dave-cushman.net/shot/303hist.html
  |title=History of the .303 British Calibre Service Ammunition Round
  |author=David Cushman
}}</ref><ref name="leeenfield2010">{{cite web|url=http://www.enfieldrifles.ca/ti5.htm |title=Rifle, Short Magazine Lee–Enfield |publisher=The Lee–Enfield Rifle Website |access-date=13 May 2010}}</ref><ref>[https://vickersmg.blog/manual/range-tables/ The Vickers Machine Gun Range Tables]</ref> The Mk VII was different from earlier .303 bullet designs or spitzer projectiles in general. Although it appears to be a conventional spitzer-shape full metal jacket bullet, this appearance is deceptive: its designers made the front third of the interior of the Mk 7 bullets out of aluminium (from Canada) or ''[[tenite]]'' (cellulosic plastic), wood pulp or compressed paper, instead of lead and they were autoclaved to prevent wound infection. This lighter nose shifted the [[centre of gravity]] of the bullet towards the rear, making it tail heavy. Although the bullet was stable in flight due to the [[gyroscopic]] forces imposed on it by the [[rifling]] of the barrel, it behaved very differently upon hitting the target. As soon as the bullet hit the target and decelerated, its heavier lead base caused it to [[Flight dynamics|pitch]] violently and deform, thereby inflicting more severe [[Ballistic trauma|gunshot wounds]] than a standard single-core spitzer design.<ref>{{Cite web | url=https://www.theboxotruth.com/the-box-o-truth-37-the-deadly-303-british-and-the-box-o-truth/ |title = The Box O' Truth #37 - the Deadly .303 British and the Box O' Truth|date = 13 June 2014}}</ref> The Mk VII bullet was considered to be in compliance of the [[Hague Conventions of 1899 and 1907|Hague Convention]] as its metal jacket completely covered the cores. The convention only prohibited "the use of bullets which can easily expand or change their form inside the human body such as bullets with a hard covering which does not completely cover the core...".<ref>{{cite web|url=http://www.minbuza.nl/en/key-topics/treaties/search-the-treaty-database/1899/7/002423.html|title=Declaration concerning the prohibition of the use of bullets which can easily expand or change their form inside the human body such as bullets with a hard covering which does not completely cover the core, or containing indentations|first=Ministerie van Buitenlandse|last=Zaken|website=www.minbuza.nl|access-date=7 April 2022|archive-url=https://web.archive.org/web/20131209005345/http://www.minbuza.nl/en/key-topics/treaties/search-the-treaty-database/1899/7/002423.html|archive-date=9 December 2013|url-status=dead}}</ref> It was noted by German Professor K. Stargardt in December 1914 that the Mk VII bullet would routinely "...disintegrate on the lightest contact with a firm body, such as a bone," resulting in an "explosive effect," and leaving artillery-like fragmentation in the body.<ref>{{cite journal |last1=Stargardt |first1=K |title=The English Infantry Bullets and Their Action |journal=BMJ Military Health |date=1915 |volume=24 |pages=601–604}}</ref>{{efn| This performance is very similar to many more modern military bullet designs, such as the 5.56mm M193 bullet, the 5.56mm M855 bullet, the 5.56mm M855A1 bullet, the 7.62mm DM111 bullet, and the 7.62mm M80A1 bullet, which are designed to break apart at the crimp cannelure and fragment.<ref>{{cite web |title=Reading Gunshot Patterns |url=https://www.nlm.nih.gov/visibleproofs/galleries/technologies/patterns_image_5.html |publisher= National Institute of Health |access-date=7 April 2022 |archive-url=https://web.archive.org/web/20100824053701/http://www.nlm.nih.gov/visibleproofs/galleries/technologies/patterns_image_5.html |archive-date=24 August 2010 |url-status=live}}</ref>{{original research inline |date=April 2022}}<ref name="LibertyAmmunitionVUS">{{cite court |litigants=LIBERTY AMMUNITION, INC., v UNITED STATES |vol= |reporter= |opinion=11-84c |pinpoint= |court= |date=2011 |url=https://ecf.cofc.uscourts.gov/cgi-bin/show_public_doc?2011cv0084-112-0 |access-date=7 April 2022 |quote=Similar to the M855A1, the projectile of the M80A1 EPR employs a steel penetrator, copper slug, and reverse copper jacket that ruptures upon striking a soft target. |postscript= }}</ref> The M855A1 and M80A1 bullet designs have a dual core construction.<ref name="LibertyAmmunitionVUS"/>}}

The ''Mk VIIz'' (and later Mk VIIIz) rounds have versions utilizing {{convert|41|gr|g|2|abbr=on}} [[Improved military rifle powder#Specification numbers|Dupont No. 16]] single-base [[smokeless powder]] based on nitrocellulose flake shaped [[propellant]]s. The nitrocellulose versions—first introduced in World War I—were designated with a "z" postfix indicated after the type (e.g. Mark VIIz, with a bullet weight of {{convert|175|gr|g|2|abbr=on}}) and in [[headstamp]]s.<ref>{{cite web  |url          = http://enfieldrifles.profusehost.net/gh2.htm  |title        = The .303 British Cartridge  |access-date  = 13 May 2007  |archive-url  = https://web.archive.org/web/20070429150804/http://enfieldrifles.profusehost.net/gh2.htm  |archive-date = 29 April 2007  |url-status = dead |website=Lee-Enfield Rifle Website}}</ref>

====.276 Enfield====
.303 British cartridges, along with the [[Lee–Enfield]] rifle, were heavily criticized after the Second Boer War. Their heavy round-nosed bullets had low muzzle velocities and suffered compared to the [[7×57mm]] rounds fired from the [[Mauser Model 1895]]. The high-velocity 7×57mm had a flatter trajectory and longer range that excelled on the open country of the South African plains. In 1910, work began on a long-range replacement cartridge, which emerged in 1912 as the [[.276 Enfield]]. The British also sought to replace the Lee–Enfield rifle with the [[Pattern 1913 Enfield]] rifle, based on the Mauser M98 bolt action design. Although the round had better ballistics, troop trials in 1913 revealed problems including excessive recoil, muzzle flash, barrel wear and overheating. Attempts were made to find a cooler-burning propellant, but further trials were halted in 1914 by the onset of [[World War I]]. As a result, the Lee–Enfield rifle was retained, and the .303 British cartridge (with the improved Mark VII loading) was kept in service.<ref>{{citation |url=http://www.quarry.nildram.co.uk/256brit.htm |title=The .256 Inch British: A Lost Opportunity |archive-url=https://web.archive.org/web/20130606221212/http://www.quarry.nildram.co.uk/256brit.htm |archive-date=6 June 2013 |first=Anthony G |last=Williams |date=25 September 2010}}</ref>

===Mark VIIIz===
In 1938 the ''Mark VIIIz'' "streamline ammunition" round was approved to obtain greater range from the [[Vickers machine gun]].<ref name=Dunlap>{{cite book|last1=Dunlap|first1=Roy F. |title=Ordnance Went Up Front|publisher=Samworth Press|year=1948|page=40 |ISBN=978-1-884849-09-1}}</ref> The streamlined bullet was based on the [[7.5×55mm Swiss#The GP 11 cartridge|7.5×55mm Swiss GP11]] projectiles and slightly longer and heavier than the Mk VII bullet at {{convert|175|gr|g|2|abbr=on}}, the primary difference was the addition of a [[External ballistics#General trends in drag or ballistic coefficient|boat tail]] at the end of the bullet and using {{convert|37|to|41|gr|g|2|abbr=on}} of nitrocellulose smokeless powder as propellant in the case of the Mk VIIIz, giving a muzzle velocity of {{convert|2525|ft/s|m/s|0|abbr=on}}. As a result, the chamber pressure was higher, at {{convert|40000|to|42000|psi|MPa|1|abbr=on}}, depending upon loading, compared to the {{convert|39000|psi|MPa|1|abbr=on}} of the Mark VII(z) round.<ref>[https://sites.google.com/site/britmilammo/-303-inch/-303-inch-cordite-ball-mark-vi-to-viiiz .303 inch Ball Mark VI to VIIIz & L1A1]</ref><ref>Dunlap, Roy F., ''Ordnance Went Up Front'', Samworth Press (1948), {{ISBN|978-1-884849-09-1}} p. 40: There appear to have been two distinct loadings of the Mark VIII cartridge: one small arms expert serving with the Royal Army Ordnance Corps at [[Alexandria|Dekheila]] noted who Mk VIIIz ammunition he examined had a claimed muzzle velocity of {{convert|2900|ft/s|m/s|0|abbr=on}}, furthermore, primers on MK VIIIz fired cases he examined looked "painted on", normally indicating a pressure of around {{convert|60000|psi|MPa|1|abbr=on}}.</ref> The Mark VIIIz streamline ammunition had a maximum range of approximately {{convert|4500|yd|m|0|abbr=on}}.<ref>[https://vickersmg.blog/manual/range-tables/ The Vickers Machine Gun 1939 Range Tables]</ref> Mk VIIIz ammunition was described as being for "All suitably-sighted .303-inch small arms and machine guns" – rifles and [[Bren gun]]s were proofed at {{convert|50000|psi|MPa|1|abbr=on}} – but caused significant bore erosion in weapons formerly using Mk VII ammunition, ascribed to the channelling effect of the boat-tail projectile. As a result, it was prohibited from general use with rifles and light machine guns except when low flash was important and in emergencies.<ref name="temple">{{cite book
  |title=Identification Manual on the .303 British Service Cartridge No.1 - Ball Ammunition
  |last=Temple |first=B.A.
}}</ref> As a consequence of the official prohibition, ordnance personnel reported that every man who could get his hands on Mk VIIIz ammunition promptly used it in his own rifle.<ref name=Dunlap />

===Tracer, armour-piercing and incendiary===
[[Tracer ammunition|Tracer]] and armour-piercing cartridges were introduced during 1915, with explosive [[Pomeroy bullet]]s introduced as the Mark VII.Y in 1916.

Several incendiaries were privately developed from 1914 to counter the [[Zeppelin]] threat but none were approved until the Brock design late in 1916 as BIK Mark VII.K<ref>
{{cite book
  |chapter=Chapter 5, .303 inch Incendiary, Explosive and Observing Ammunition
  |title=.303 inch: a history of the .303 cartridge in British Service
  |last=Labbett |first=P.
  |author2=Mead, P.J.F
  |publisher=authors
  |year=1988
  |isbn=978-0-9512922-0-4
}}
</ref> Wing Commander [[Frank Arthur Brock|Frank Brock]] [[RNVR]], its inventor, was a member of the [[Brocks Fireworks|Brock]] fireworks-making family. Anti-zeppelin missions typically used machine guns loaded with a mixture of Brock bullets containing [[potassium chlorate]], Pomeroy bullets containing [[dynamite]], and Buckingham bullets containing [[pyrophoric]] yellow [[phosphorus]].<ref>{{citation |work=[[Flight International|Flight]] |date=1919 |url=https://www.flightglobal.com/FlightPDFArchive/1919/1919%20-%200895.PDF |title=The Brock Bullet Claim |via=flightglobal.com |publisher= |access-date=12 August 2018 }}</ref> A later incendiary was known as the [[Incendiary ammunition#World War II|de Wilde]], which had the advantage of leaving no visible trail when fired. The de Wilde was later used in some numbers in fighter guns during the 1940 [[Battle of Britain]].<ref>[https://www.flightglobal.com/pdfarchive/view/1946/1946%20-%201893.html The Battle of Britain - Excerpts from an Historic Despatch by Air Chief Marshal Sir Hugh Dowding],''Flight'', 19 September 1946, p323</ref>

These rounds were extensively developed over the years and saw several Mark numbers. The last tracer round introduced into British service was the G Mark 8 in 1945, the last armour-piercing round was the W Mark 1Z in 1945 and the last incendiary round was the B Mark 7 in 1942. Explosive bullets were not produced in the UK after 1933 due to the relatively small amount of explosive that could be contained in the bullet, limiting their effectiveness, their role being taken by the use of Mark 6 and 7 incendiary bullets.

In 1935, the .303 O Mark 1 Observing round was introduced for use in machine guns. The bullet to this round was designed to break up with a puff of smoke on impact. The later Mark 6 and 7 incendiary rounds could also be used in this role.

During World War I British factories alone produced 7,000,000,000 rounds of .303 ammunition. Factories in other countries added greatly to this total.<ref name="homefront">
{{cite book
  |chapter=Appendix VII, page IV, "British Military Output WWI"
  |title=Home Front - Untold Tales of British Workers during the Great Wars
  |last=Featherstone-Haugh|first=JJ.
  |publisher=OUP
  |year=1973
}}
</ref>
===Pencils===

Spent .303 cartridges were used to make cases of the bullet pencils included in some of the [[Princess Mary Christmas gift box]]es given to troops in World War 1.<ref name=Barry69>{{cite thesis |last=Barry |first=Martin N |date=September 2022 |title='A Box of Conflict Memories' - Materiality, Memory and Princess Mary's Gift Box 1914-2020 |url=https://research-information.bris.ac.uk/ws/portalfiles/portal/355223376/_A_Box_of_Conflict_Memories_.pdf |type=PhD |chapter=Bullet Pencil|pages=69–72 |publisher=University of Bristol |access-date=30 August 2023}}</ref>

==Headstamps and colour-coding==
{{unreferenced section |date=April 2022}}
[[File:.303ammunition.jpeg|thumb|.303 British Cartridge (Mk VII), manufactured by [[Colonial Ammunition Company|CAC]] in 1945]]
[[File:EnfieldNo4Mk2-303Brit.jpg|thumb|300px|Five-round [[stripper clip|charger]] ready to be loaded in a [[Lee–Enfield#Rifle_No._4|Lee–Enfield No. 4 Mk 2]] rifle]]

{| class="wikitable"
|-
! Headstamp ID !! Primer annulus colour !! Bullet tip colour !! Other features !! Functional type
|-
| VII or VIIZ || Purple || None || None || Ball
|-
| VIIIZ || Purple || None || None || Ball
|-
| G1, G2, G3, G7 or G8 || Red || None || None || Tracer
|-
| G4, G4Z, G6 or G6Z || Red || White || None || Tracer
|-
| G5 or G5Z || Red || Grey || None || Tracer
|-
| W1 or W1Z || Green || None || None || Armour-piercing
|-
| VIIF or VIIFZ || None || None || None || Semi-armour piercing (1916–1918)
|-
| F1 || Green || None || None || Semi-armour piercing (1941)
|-
| B4 or B4Z || Blue || None || Step in bullet jacket || Incendiary
|-
| B6 or B6Z || Blue || None || None || Incendiary
|-
| B7 or B7Z || Blue || Blue || None || Incendiary
|-
| O.1 || Black || Black || None || Observing
|-
| PG1 or PG1Z || Red || None || Blue band on case base || Practice-tracer
|-
| H1Z || None || None || Front half of case blackened || Grenade discharger
|-
| H2 || None || None || Entire case blackened || Grenade discharger
|-
| H4 || None || None || Case blackened {{convert|3/4|in|mm|abbr=on}} from each end || Grenade discharger
|-
| H7Z || None || None || Rear half of case blackened || Grenade discharger (v.powerful load)
|}

==Japanese 7.7 mm ammunition==
[[File:7.7 mm Japanese navy.jpg|right|thumb|Cutaways of the five types of ammunition produced in Japan]]
[[Imperial Japanese Navy Air Service]] adopted [[Ro-Go Ko-gata]] seaplane armed with a .303 MG in 1918, and the calibre was common on surplus [[List of World War I Entente aircraft|Entente aircraft]] acquired by the [[Imperial Japanese Army Air Service]] after WWI, so its usage continued during the [[Interbellum]], and on naval aircraft even throughout WWII. Japan produced a number of machine guns that were direct copies of the British [[Lewis Gun|Lewis]] (Japanese [[Type 92 machine gun]]) and [[Vickers machine gun]]s as well as ammunition for them. The 7.7&nbsp;mm cartridge used by the Japanese versions of the British guns is a direct copy of the .303 British (7.7×56mmR) rimmed cartridge and is distinctly different from the [[7.7×58mm Arisaka]] rimless and [[7.7×58mm Arisaka#7.7×58mm Type 92|7.7×58mm Type 92]] semi-rimmed cartridges used in other Japanese machine guns and rifles.<ref>Walter H.B. Smith, ''Small Arms of the World'', Stackpole Publications.</ref>
* ''Ball'': {{convert|174|gr}}. Cupro-nickel jacket with a composite [[aluminium]]/[[lead]] core. Black primer.
* ''Armour-piercing.'': Brass jacket with a steel core. White primer.
* ''Tracer'': {{convert|130|gr}}. Cupro-nickel jacket with a lead core. Red primer.
* ''Incendiary'': {{convert|133|gr}}. Brass jacket with white phosphorus and lead core. Green primer.
* ''[[High Explosive|H.E.]]'': Copper jacket with a [[PETN]] and lead core. Purple primer.

Note: standard Japanese ball ammunition was very similar to the British Mk 7 cartridge. The two had identical bullet weights and a "tail-heavy" design, as can be seen in the cut-away diagram.

==Civilian use==
The .303 cartridge has seen much sporting use with surplus military rifles, especially in Australia, Canada, New Zealand, and to a lesser extent in the United States and South Africa. In Canada, it was found to be adequate for any game. In Australia, it was common for military rifles to be re-barrelled in [[.303/25]] and [[.303/22]]. However the .303 round still retains a considerable following as a game cartridge for all game species, especially [[Sambar deer]] in wooded country.  A change.org petition asking [[Lithgow Arms]] to chamber the LA102 centrefire rifle in .303 as a special edition release has attracted considerable attention both in Australia and worldwide.  In South Africa, .303 Lee–Enfield rifles captured by the Boers during the [[Second Boer War|Boer War]] were adapted for sporting purposes and became popular with many hunters of non-dangerous game, being regarded as adequate for anything from the relatively small [[impala]] to the massive [[Common Eland|eland]] and [[Greater Kudu|kudu]].<ref>{{cite web|last=Hawks|first=Chuck|title=Matching the Gun to the Game|url=http://www.chuckhawks.com/gun_game.htm|work=ChuckHawks.com|access-date=6 September 2010| archive-url= https://web.archive.org/web/20100820215156/http://www.chuckhawks.com/gun_game.htm| archive-date= 20 August 2010<!--Added by DASHBot-->}}</ref>

===Commercial ammunition ===
{{unreferenced section|date=May 2014}}
[[File:303 British stripper clip, civilian sporting rounds.JPG|right|thumb|Commercial [[soft point]] .303 British loaded in a [[Lee–Enfield]] five-round charger.]]
[[File:303 British.jpg|right|thumb|upright=0.6|Civilian [[soft point]] .303 ammunition, suitable for hunting purposes.]]

The .303 British is one of the few (along with the [[.22 Hornet]], [[.30-30 Winchester]], and [[7.62×54mmR]]) bottlenecked rimmed centrefire rifle cartridges still in common use today. Most of the bottleneck rimmed cartridges of the late 1880s and 1890s fell into disuse by the end of the First World War. Commercial ammunition for weapons chambered in .303 British is readily available, as the cartridge is still manufactured by major producers such as [[Remington Arms|Remington]], [[Federal Cartridge|Federal]], [[Olin Corporation|Winchester]], [[Sellier & Bellot]], Denel-PMP, [[Prvi Partizan]] and [[Wolf Ammunition|Wolf]]. Commercially produced ammunition is widely available in various [[full metal jacket bullet]], [[soft point]], [[hollow-point bullet|hollow point]], flat-based and [[External ballistics#General trends in drag or ballistic coefficient|boat tail]] designs, both spitzer and round-nosed.

===Hunting use===
The .303 British cartridge is suitable for all medium-sized game and is an excellent choice for [[whitetail deer]] and [[American black bear|black bear]] hunting. In Canada it was a popular moose and deer cartridge when military surplus rifles were available and cheap; it is still used. The .303 British can offer very good penetrating ability due to a fast twist rate that enables it to fire long, heavy bullets with a high [[sectional density]]. [[Canadian Rangers]] use it for survival and [[polar bear]] protection. In 2015, the Canadian Rangers began the process to evaluate rifles chambered for [[.308 Winchester]]. The Canadian Department of National Defence has since replaced the previously issued [[Lee–Enfield#Rifle No. 4|Lee–Enfield No. 4]] rifles with the [[Colt Canada C19]] chambered as evaluated in [[7.62×51mm NATO]]/[[.308 Winchester]].<ref>[https://ottawacitizen.com/news/national/defence-watch/here-it-is-the-new-sako-rifle-for-the-canadian-rangers Here it is – the new Sako rifle for the Canadian Rangers]</ref>

==Rounds developed from .303==
===Pre-WWI sporting rounds===
During the 1890s, Scottish gunsmith Daniel Fraser developed a rimless version of the cartridge known as ".303 Fraser Velox" or ".303 Fraser Rimless", loaded with a bullet of his own oblique ratchet design to enhance expansion which was patented in 1897<ref>{{cite web | url=https://sportingclassicsdaily.com/down-goes-fraser | title=Down Goes Fraser | first= L.D. |last=McCaa  | date=27 December 2016 |website=sportingclassicsdaily.com }}</ref><ref>{{cite web | url=https://www.sajagterhunter.com/undisputed-daniel-fraser-of-edinburgh | title=Undisputed-Daniel Fraser of Edinburgh |website=sajagterhunter.com |date=November–December 2021 | first= Hubert |last=Montgomery}}</ref><ref>{{patent|GB|189704971A}}</ref> The bullet was also used in a proprietary loading of .303 British marketed as ".303 Fraser Flanged".<ref>{{cite web | url=https://www.cartridgecollector.net/303-fraser-flanged | title=303 Fraser Flanged |website= Cartridgecollector.net }}</ref>

Proprietary loadings of .303 British include the ".303 Marksman" by [[Eley Brothers]] from before 1908.<ref>{{cite web | url=http://www.acant.org.au/Articles/Other303Cartridges.html | title=The Other .303 Cartridges }}</ref> and ".303 Swift" from before 1911.<ref>{{cite web | url=https://www.cartridgecollector.net/303-swift | title=303 Swift |website=  Cartridgecollector.net }}</ref>

In 1899, the British service round was lengthened and necked-out to create the [[.375 Flanged Nitro Express]] hunting cartridge for single-shot and double rifles. Around 1905, it was necked down back to create [[.375/303 Westley Richards Accelerated Express]].{{citation needed|date=May 2022}}

===Post-1917 military experiments===
In 1917, design work started on a more powerful military cartridge of the same calibre and overall length.{{cn|date=June 2022}} In 1918 it was planned that the new round, also retaining the old rim diameter, would be used in rechambered P14 rifles with AP rounds to defeat German targets on the battlefield of WWI as well as in the RAF in modified Lewis gun. The cartridge was "produced in quantity" but not adopted formally. The case was 62mm long with the bullet (a Ball Mark VII or Mark VIIW) set deep within to keep overall length down. The ordinary round was designated "Cartridge S.A. ball .303 inch Rimless" despite the fact that it retained headspacing on its rim and was  [[Rim (firearms)#Semi-rimmed|semi-rimmed]].<ref name=".303Rimless">{{cite web | url=https://sites.google.com/site/britmilammo/-303-inch-rimless | website=British Military Small Arms Ammo |title= .303 inch Rimless }}</ref>  It is better known{{cn|date=June 2022}} today under names like ".303 Lewis Semi-Rimmed".
{{expand section|date=May 2022}}

===Post-1945 Australian wildcats===
After WWII, Australians found themselves with quite a few .303" service rifles but at the same time new [[Gun laws of Australia|legal restrictions]] on military ammunition, which led to development of many [[wildcat round]]s,<ref>{{cite web | url=https://www.cartridgecollector.net/cartridges-based-303-british | title=Cartridges based on the .303 British |website=  Cartridgecollector.net }}</ref> the best-known of which are [[.303/25]] and [[.303/22]].{{cn|date=June 2022}}
{{expand section|date=May 2022}}

===Post-1945 South African developments===
In parallel to Australia, the same wildcatting was happening in other countries of the Commonwealth, and in 1969 [[Pretoria Metal Pressings]] started factory production of a .303 necked down to 6&nbsp;mm (.243") under the name of [[6 mm Musgrave]].<ref>{{cite web | url=https://www.cartridgecollector.net/6mm-musgrave | title=6mm Musgrave |website=  Cartridgecollector.net }}</ref>
{{expand section|date=May 2022}}

===.303 Epps===
Canadian Ellwood Epps, founder of Epps Sporting Goods, created an improved version of the .303 British.{{when|date=May 2022}} It has better ballistic performance than the standard .303 British cartridge. This is accomplished by increasing the shoulder angle from 16 to 35 degrees, and reducing the case taper from {{convert|.062|in|mm}} to {{convert|.009|in|mm}}. These changes increase the case's internal volume by approximately 9%. The increased shoulder angle and reduced case taper eliminate the drooping shoulders of the original .303 British case, which, combined with reaming the chamber to .303 Epps, improves case life.<ref>{{Cite web |url=https://www.303british.com/id20.html |title=303 Epps - Notes on Improved Cases |access-date=23 April 2018 |archive-url=https://web.archive.org/web/20170702065219/http://www.303british.com/id20.html |archive-date=2 July 2017 |url-status=dead |website=303British.com }}</ref>

==Firearms chambered in .303 British==

{{div col|colwidth=25em}}
* [[1885 Courteney Stalking Rifle]]
* [[Bren light machine gun]]
* [[M1919 Browning machine gun|Browning Model 1919 machine gun]] aircraft version
* [[BSA Autorifle]]
* [[Ross rifle|Canadian Ross Rifle Mk I through III]]
* [[Caldwell machine gun]]
* [[Charlton Automatic Rifle]]
* [[Darne machine gun]]
* [[Farquharson rifle]]
* [[Globco Mohawk 555]]
* [[Hotchkiss M1909 Benét–Mercié machine gun|Hotchkiss .303 Mk I & I*]]
* [[Huot automatic rifle]]
* [[Jungle carbine]]
* [[Lee–Enfield]] rifle
* [[Lee–Metford]] rifle
* [[Lewis gun]]
* [[McCrudden light machine rifle]]
* [[Martini–Enfield]] rifle
* [[Pattern 14 Rifle|P14 rifle]]
* [[Parker Hale]] Sporter Rifle
* [[Ruger No. 1]]
* [[Thorneycroft carbine]]
* [[Vickers-Berthier]] light machine gun
* [[Vickers machine gun]]
* [[Vickers K machine gun]]
* [[Winchester Model 1895]]
{{div col end}}

==See also==
* [[7 mm caliber]] (overview of cartridges)
* [[7.65×53mm Mauser]]
* [[8×59mm Rb Breda]]
* [[British military rifles]]
* [[List of rifle cartridges]]
* [[List of rimmed cartridges]]
* [[Table of handgun and rifle cartridges]]
* [[.303 Magnum]]
* [[.303 Savage]]

==Notes==
{{notelist}}

==References==
{{reflist}}

==External links==
{{Commons category}}
* {{cite web
  |url=http://www.theboxotruth.com/docs/edu30.htm
  |title=Photos of the contents of different .303 British cartridges
  |publisher=Box of Truth website
  |date=13 June 2014
  |access-date=13 October 2007
  |archive-date=7 April 2014
  |archive-url=https://web.archive.org/web/20140407094702/http://www.theboxotruth.com/docs/edu30.htm
  |url-status=dead
  }}
* {{cite web
 |url          = http://www.brassfetcher.com/Sellier%20&%20Bellot%20150gr%20Soft-point.html
 |title        = Photo of Sellier & Bellot 150&nbsp;gr (9.7&nbsp;g) .303 British soft-point fired into ballistic gelatin (bullet travelled right to left)
 |access-date  = 21 August 2018
 |archive-url  = https://web.archive.org/web/20081219112454/http://www.brassfetcher.com/Sellier%20%26%20Bellot%20150gr%20Soft-point.html
 |archive-date = 19 December 2008
 |url-status     = dead}}
* {{cite web
  |url=http://www.conjay.com/Ammunition%20for%20Armor%20Testing%20WW2%20303.htm
  |title=Photos of various different types of .303 ammunition
  |access-date=10 April 2007
  |archive-date=12 November 2020
  |archive-url=https://web.archive.org/web/20201112015356/http://www.conjay.com/Ammunition%20for%20Armor%20Testing%20WW2%20303.htm
  |url-status=dead
  }}
* {{cite web
 |url       = http://www.cybertorpedo.com/africanhunter/firearms/303_british_rifle_01.htm
 |archive-url = https://web.archive.org/web/20060314115906/http://www.cybertorpedo.com/africanhunter/firearms/303_british_rifle_01.htm
 |url-status  = dead
 |archive-date = 14 March 2006
 |title     = Africa
 |publisher = Sniper Central
}}
* {{cite web
  |url=http://www.303british.com
  |title=.303 British
  |publisher=303british.com
}}
* {{cite web
  |url=http://www.dave-cushman.net/shot/303headstamps.html
  |title=Headstamps of various .303 ammunition producers
  |author=David Cushman
}}
* [http://www.worldwar.it/sito/munizioni/giapponesi/77-x-56-r-tipo-89-giapponese 7,7 x 56 R Tipo 89 Giapponese]
* [http://www.cip-bobp.org/homologation/uploads/tdcc/tab-ii/tabiical-en-page74.pdf C.I.P. TDCC datasheet .303 British] (PDF)
* [https://web.archive.org/web/20141225231536/http://www.saami.org/PubResources/CC_Drawings/Rifle/303%20British.pdf SAAMI Drawing 303 British] (PDF)
* [https://www.iwm.org.uk/collections/item/object/30026287 .303 Rimless]
* [https://www.acant.org.au/Articles/Other303Cartridges.html THE OTHER .303 CARTRIDGES]
* [https://www.reddit.com/r/CryptidGuns/comments/xq0yne/1911_bsa_autorifle_not_bsathompson_with_a/]

{{WWI British Empire small arms}}
{{WW2 Brit Comm Infantry Guns}}
{{Rimmed cartridges}}

{{DEFAULTSORT:303 British}}
[[Category:.303 British firearms]]
[[Category:British firearm cartridges]]
[[Category:Military cartridges]]
[[Category:Pistol and rifle cartridges]]
[[Category:Rimmed cartridges]]
[[Category:Weapons and ammunition introduced in 1889]]