British 303 Cartridge Case Identification – Headstamps and Much More!

Identification of British .303 inch ammunition can be quite challenging, especially for the beginner. The .303 began life as far back as 1889 and was originally used in the Lee-Metford rifle. Since then it has under gone a number of changes, with a wide variety of bullet types, and is still produced today. It was the main cartridge used by the British army until it was finally replaced in the 1950s by the 7.62×51 Nato cartridge.

The general dimensions of the .303 cartridge are as follows;

Case typeRimmed, bottleneck
Bullet diameter7.92 mm (0.312 in)
Neck diameter8.64 mm (0.340 in)
Shoulder diameter10.19 mm (0.401 in)
Base diameter11.68 mm (0.460 in)
Rim diameter13.72 mm (0.540 in)
Rim thickness1.63 mm (0.064 in)
Case length56.44 mm (2.222 in)
Overall length78.11 mm (3.075 in)

The official nomenclature for the cartridge is the 303 British or 7.7x56R (7.7mm calibre, 56mm case length, rimmed).

The main method of identification to determine the origin and type of 303 cartridge is the headstamp, which will be dealt with later. Other identifying features of the cartridge are the annulus (ring around the primer) colour, bullet tip colour and the colour of the cartridge case itself.

ANNULUS COLOUR

The primer of a cartridge case initiates the main propellent when the firing pin of a weapon impacts against it. There are numerous terms used for the primer, but in British service it is known as the ‘cap’.

A varnish is used to seal the cap in place in the cartridge case, and it wasn’t until the latter stages of WW1 that colour was added to this varnish to help identify different loadings. The ‘ring’ that surrounds the cap is known as the annulus.

COLOURLOAD
PurpleBall and short range practice ball
RedTracer (also some explosive rounds)
GreenArmour-piercing and semi armour-piercing
BlueIncendiary
BlackExplosive and observation
YellowProof and standard
OrangeSome explosive rounds
ClearBlank

Bullet Tip Colour

As more and more variants were added, it became necessary to identify loadings via as quick a method as possible. The use and variation in colour tips increased greatly during WW2, with coloured tips becoming more and more prevalent as the war progressed

COLOURLOAD
WhiteTracer G Mark IV and VI (daytime tracer)
GreyTracer G Mark V (night-time tracer)
RedCanadian tracer G Mark II and some British G Mark II
BlueIncendiary B Mark VII and VIIz
GreenArmour-Piercing W Mark Iz, but only used for export contracts, not British service
BlackObservation Mark I
Orange/YellowBelieved to be night tracer

Case colour

The 303 comes in a variety of coloured, part-coloured and plated forms.

Black staining to case

The use of a chemical staining method to colour portions, (or the whole), of the cartridge case has been used since 1904, when the Blank Mark VI was introduced. Staining parts or the whole of the cartridge black helps in quick identification of the cartridge type.

MarkingCartridge
Top half blackened, open neckRifle grenade H Mark I
Whole case blackened, open neckRifle grenade H Mark II
Top and bottom thirds blackened, rosette crimpRifle grenade H Mark 4 & 4z
Bottom half blackened, rosette crimpRifle grenade H Mark 7z
Bottom half blackened, open neckDischarger smoke generator E I.T
Whole case blackened, brass mock bulletBlank Mark VI (pre 1907)
Whole case blackened, rosette crimpBlank Mark VI (post 1907)
Top third blackened, bulletedShort range practice
Bottom third blackened, bulletedMatch ammunition
Top and bottom thirds blackened, bulletedMatch ammunition
Rifle grenade H Mark I
Rifle grenade H Mark II
Rifle grenade H Mark 4 & 4z
Rifle grenade H Mark 7z
Discharger smoke generator E I.T
Blank Mark VI (pre 1907)
Blank Mark VI (post 1907)

Some 303 drill rounds were also blackened.

MarkingCartridge type
Blackened case and bullet, 4 holes drilled in cartridge caseDummy drill Mark V (WW1)
Blackened case and bullet, six narrow flutes extending from shoulderDrill round, produced by Colonial Ammunition Company, New Zealand during WW2
Blackened cartridge case and bulletDrill round, produced by Winchester repeating Arms USA, supplied on contract in WW2

303 cartridges were also produced with coloured rings around the cartridge case. The colour used can be purple, red, green or black. This was mainly a Canadian manufacturers practice, and usually denoted match ammunition. However, one exception to this was the Canadian tracer G Mark I made by the Dominion Arsenal early in WW2. This had a black band painted around the case, 8mm wide, approximately 10mm above the rim.

The British manufactured 303 cartridges saw two cases with blue bands. The Practice Tracer PG Mark I had a 6mm blue band just above the rim, and the Reduced Charge Ball had a 1 inch blue band around the case. This second cartridge was used to cause a deliberate jam in a Vickers MG to train RFC aircrew in clearing a jam in the air.

Chromed, Silvered or White Metal Cases

A chromed, silvered or white case denoted a Dummy Drill or Inspection cartridge and is usually accompanied by fluting or holes drilled through the cartridge. The fluting was often painted red to highlight it.

Dummy Drill Mark IEmpty brass case, tinned, no cap, coreless bullet
Dummy Drill Mark IIEmpty brass case, tinned, no cap, coreless bullet, case coned and indented to secure bullet
Dummy Drill Mark IIIPlain (Pre 1907) or red (post 1907) round nosed wooden bullet. Case usually brass but was tinned prior to 1905.
Dummy Drill D Mark VIChromed or cupro-nickel case, jacketed spitzer bullet, three vertical flutes, (usually painted red)
Drill D Mark VII & VIINCupro-nickel jacketed bullet with aluminium core, chromed case with three red flutes, empty cap recess sometimes painted red. N denoting naval service
Drill D Mark IXWW2 expedient. Can be found as plain brass or tinned/chromed cases
Drill D Mark 10Chromed case with three red flutes. Gilding metal jacketed bullet with empty cap chamber, sometimes painted red
Drill D 1942 Canadian patternChromed case with three flutes
Dummy Inspectors Mark ITinned brass case, filled with coal dust, round nosed bullet
Dummy Inspectors Mark IITinned brass case, filled with coal dust, round nosed bullet
Dummy Inspectors Mark IIITinned brass case, filled with coal dust, round nosed bullet
Dummy Inspectors Mark IVTinned brass case, filled with coal dust, pointed bullet
Dummy Inspectors U Mark 5 or VWhite metal case, blind cap chamber (sometimes painted red), manufactured to normal weight of standard 303 ball

There are other types of finish in 303 cartridges. Polished steel cases were used as armourers tool cartridges and copper washed cartridges were used as proof cartridges.

Headstamps

The headstamp of a cartridge is the major identifier of the manufacturer, year and loading. During the life of the 303 cartridge, it evolved through several steps.

The original 303 Powder Mark I cartridges (manufactured between 1889 and 1890) showed the manufacturers code of RL, (Royal Laboratory, Woolwich),separated by a War Department (broad) arrow at the 12 o’clock position, along with the last two digits of the year of manufacture at the 9 and 3 o’clock positions. There may also be a number at the six o’clock position, showing the case was supplied by a contractor.

The Powder Mark II ball round was manufactured between 1891 and 1893 and showed only the manufacturer and mark number, along with a broad arrow.

In 1891 the Cordite Ball Mark I round was introduced, making it necessary to identify the higher velocity cordite filled rounds. Headstamps included the manufacturer and the letter ‘C’ without a mark number, but this was added very soon after, leading to a headstamp with the manufacturer identifier at 12 o’clock, letter ‘C’ at 7 o’clock and mark number at 5 o’clock. With the production switching entirely to cordite rounds in 1907/8, the ‘C’ was dropped from the headstamp as it became meaningless.

The headstamp also altered the same year to include the year of manufacture, shown as the last two digits of the year at the 2 o’clock position. At the same time, the headstamp of cartridges intended for military use were overstamped with one or two broad arrows. These could appear anywhere on the headstamp and often obliterated other information.

The next change came during WW1 with the appearance of different loadings. These were identified in the headstamp by adding a suffix after the mark number.

SuffixLoad
A.APomeroy incendiary P.S.A. Mark II
BBuckingham incendiary
FKings Norton Semi-Armour Piercing
GS.P.G. Tracer
KBrock incendiary
PKynoch Armour-Piercing
R.C.Reduced Charge
R.T.S.Explosive (Richard Threlfall & Son)
R.T.T.Explosive (Richard Threlfall Todhunter)
SRoyal Laboratory Armour Piercing
TS.P.K. ‘Sparklet’ tracer
WArmour Piercing
YPomeroy Incendiary P.S.A. Mark I

The use of the suffix to the Mark VII headstamp continued until 1926, when an identifier letter and Mark number for each individual load replaced the suffix system. These suffix letters became the new identifier for their specific loads, followed by a mark number for that load. So, for instance, the Armour-Piercing headstamp VIIW became W I (W Mark I). For a very short period at the end of 1926, both the new style coding and previous suffix coding were stamped together, for example VIIGI for tracer Mark I.

PrefixLoad
BIncendiary
DDrill
ESmoke Generator Discharger
FSemi Armour Piercing
GTracer
HRifle Grenade
LBlank
OObservation
PPractice
QProof
RExplosive
UInspector’s Dummy
WArmour Piercing

This system continued until the beginning of 1945, when the Roman numerals were replaced with Arabic numerals, so the VII became 7.

There were two other letters that could appear on a 303 headstamp. The first, the letter ‘Z’ was used to denote the propellant loaded was nitro-cellulose. Interestingly, all 303 cartridges manufactured under contract from the US were loaded with nitro-cellulose, but did not utilise the ‘Z’ code, it was only British manufacturers that did so. The other letter is a ‘T’, used to denote a black powder fill. This was only used in special loads, most notably blanks,

MarkingPropellant
Undated, no code Black powder
Undated, code ‘C’Cordite
Dated, no codeCordite
Dated, code ‘Z’Nitrocellulose
Dated, code ‘T’Black powder

The final evolution of the 303 headstamp came in 1954 when the NATO ‘L..A..’ system was adopted. The ‘L’ number showed the type of store and the ‘A’ number reflected the modification level. For instance, the British L2A2 7.62mm ball round had the code L2 identifying it as 7.62mm ball, and the A2 showed it was the second mark.

The Date

Much speculation has surrounded the way the date appears on 303 headstamps, with many believing a 4 digit year code denoted RAF use. This was only partly true, and stemmed from the use of synchronised machine guns used by the RFC in WW1. Due to the need to have precise firing times to allow firing through a propeller, only high quality ammunition giving consistent ignition times could be used. This ammunition was manufactured to the tightest tolerances and identified with a green packaging label. From 1918 onwards the label was switched to red and the cartridges identified by use of a four digit year code. The labels were marked with ‘RAF Special’ or just ‘Special’. In 1939 when WW2 was imminent, it was decided to manufacture all 303s to Air Service tolerances and use the four digit date code. In 1942 a further directive instructed all manufacturers to use only a 2 digit date code from January 1943, and so the four digit code disappeared. It can therefore be said that all 303 ammunition dated 1939 or earlier and using a 4 digit code was for RAF use, but anything after that was for use in any of the services. It is also interesting to note that the RAF only kept cartridges on store for 2 years, after which time any unused cartridges were passed to the army. So just because you find a fired four digit date coded 303 does not necessarily mean it came from an RAF aircraft!

Manufacturer Codes

GREAT BRITAIN

Note that some of the manufacturers in this list had a number of different headstamp codes, utilised at various points during their existence.

Note the War Department Broad Arrow mark, often referred to as the ‘Crow’s Foot’, is shown in graphical form below as .

CodeManufacturerPeriod Used
Ministry of Supply Factory, Radway Green, Cheshire1940-41
Ministry of Supply Factory, Spennymoor, Yorks1940-42
BBirmingham Metal and Munitions Co. Ltd1892-1918
BEMinistry of Supply Factory, Blackpole, Worcs (cases supplied by RG)1939-45
B  EMinistry of Supply Factory, Blackpole, Worcs (cases supplied by K4)1939-45
BEMinistry of Supply Factory, Blackpole, Worcs, (cases supplied by own factory)1939-45
BMBritish Munitions Company1890s
BPDBombrini Parodi Delfino1980s
CPCrompton Parkinson, Doncaster, Yorks1939-45
C-PCrompton Parkinson, Guisley, Yorks1939-45
EEley Brothers1890s-1918
E  BEley Brothers1889
GGreenwood & Batley Ltd, Leeds, Yorks1890-1920
GAGrenfell & Accles Ltd, Birmingham1890s
GBGreenwood & Batley Ltd, Leeds, Yorks1890s-1958
HNMinistry of Supply Factory, Hirwaun, South Wales1939-45
HXPGreek Powder & Cartridge Company1980s
JBirmingham Metals and Munitions Co. Ltd., Waltham, Essex1914-1918
KGeorge Kynoch Ltd, Birmingham1890-1920
KKynoch Division of ICI Ltd, Birmingham1920-76
K2Kynoch, ICI, Standish, Lancs1939-45
K4Kynoch ICI, Yeading, Middlesex1939-45
K5Kynoch ICI, Kidderminster, Worcs1939-45
KNKings Norton Metal Co.1890-1920
LLorenz Ammunition Ordnance Co., Millwall, London1890s
MMorris Patent Tube Co. Ltd, Birmingham1890s
MNobel Explosives Ltd., Glasgow1914-18
NNobel Explosives Ltd., Glasgow1914-18
RGMinistry of Supply Factory (later Royal Ordnance Factory), Radway Green, Cheshire1942-73
RL Royal Laboratory, Woolwich1888-1954
RL.(date).Royal Laboratory, Cartridge Factory No 3, Woolwich1917-18
R(Date)LRoyal Laboratory, Cartridge Factory No 5, Woolwich1915-18
RWRudge Whitworth Cycle Co., Nottingham1939-45
SRMinistry of Supply Factory,Spennymoor, Yorks1939-45

India and Pakistan

Production of 303 cartridges commenced in India around 1895, with a characteristic government mark approved for use. This consisted of a capital letter I, above which was the Broad Arrow.

Indian Ordnance mark

There is a subtle difference between Indian and British headstamps, with the Indian ones carrying the month of manufacture, as well as the year.

CodeFactoryDate
DDum Dum Arsenal, Calcutta1895-1913
DFDum Dum Arsenal, Calcutta1895-1913
KKirkee Arsenal1895-1914
KFKirkee Arsenal1895-1960
NDum Dum Arsenal, Northern Circuit1895-1914
OKOrdnance Factory, Khamaria, Jubbulpore1943-1970s
P.O.F.Pakistan Ordnance Factory1947 onwards
SKirkee Arsenal, Southern Circuit1895-1913

Canadian

The earliest known date for Canadian 303 production is 1894. The headstamps of Canadian 303s followed the British system, even using the broad arrow initially. However, following incorporation of Canada as a Dominion, the government ownership mark changed to a C incorporating the broad arrow.

Canadian Ordnance Mark

During WW2 the Canadians used several variant headstamp arrangements. As an example, from 1943 the Defence Industries used only the manufacturer, year and ‘Z’ nitrocellulose code.

CodeManufacturerPeriod Used
DDominion Cartridge Company1918
DADominion Arsenal, QuebecPre 1940 and post 1945
DAC (The C is as above)Dominion Arsenal, Quebec1920-45
DALDominion Arsenal, Lindsey1917-21
DCDominion Cartridge Company1895-1918
DCDominion Cartridge Factory (Dominion Arsenal post 1900)1890s
DCA (The C as above)Dominion Arsenal, Quebec1935
DIDefence Industries Ltd.1940-45
LAC (The C as above)Dominion Arsenal, Lindsey1914-17
RR CoRoss Rifle Co., Quebec1915-17

Australia & New Zealand

AF Small Arms Ammunition Company, FootscrayJan 1924- Feb 1925
CACColonial Ammunition Company, Footscray1890-1920
CACColonial Ammunition Company, Auckland1898-1950s
FSAAF FootscrayMar 1925 – April 1926
FSAAF Footscray1926
MFSAAF No 1 FootscrayMay 1926-62
MF1SAAF No 1 Footscray1940
MF2SAAF No 2 Footscray1940
MGSAAF No 2 Footscray1940-48
MHSAAF No 3 Hendon1940-45
MJSAAF No 4 Hendon1941-44
MQSAAF No 5 & 6 Rocklea1942-43
MSSalisbury Explosives Factory1944
MWSAAF No 7 Welshpool1942-45
SAAFSAAF Footscray1921-23

South Africa

CodeManufacturerDate Used 
AArmscor1975-80
PMPPretoria Metal Pressings Pty, Pretoria1965-75
SAMSouth African Mint, Pretoria1961-65
USouth African Mint, Pretoria1938-42 and 1945-61
USouth African Mint, Kimberley1941
U South African Mint, Kimberley1942-45

USA

US companies produced millions of rounds of 303 for both World Wars. Virtually all the ammunition produced was standard ball ammunition.

CodeManufacturerDate Used
HNational Brass and Copper Tube Co., Hastings, NY1916
PPeters Cartridge Co., Kings Mills, Ohio1915-17
PCPeters Cartridge Co., Kings Mills, Ohio1940
RARemington Arms Co., Bridgeport, Connecticut1915-17
URemington Arms Co., Bridgeport, Connecticut1915
USUnited States Cartridge Co., Lowell, Massachusetts1915-17
WWinchester Repeating Arms Co., New Haven, Connecticut1914-17
WCCWestern Cartridge Co., East Alton, NY1940-43
WRAWinchester Repeating Arms Co., New Haven, Connecticut1940-43

Inner Case Stamps

During the second world war, companies shipped supplies between each other. Because of this, the loading company and case manufacturer could be completely different factories. As a result, a small identifier was stamped between the fire holes as an ‘identifier’. These stamps are shown below.

CodeManufacturer
GGreenwood & Batley
KICI Kynoch
RM.o.S.F. Radway Green
SM.o.S.F. Spennymoor (the ‘S’ was usually a mirror image)
2ICI Kynoch, Standish
4ICI Kynoch, Yeading
5ICI Kynoch, Kidderminster
Royal Laboratory, Woolwich

Bullet Base Stamps

Throughout the life of the 303, most bullets for ball ammunition had a makers make stamped into the lead base during the manufacture process.These stamps are shown below;

CodeManufacturer
Royal Laboratory, Woolwich (also found with a * or other mark beneath the arrow)
1Unknown manufacturer (Round nosed bullets)
1Government Cartridge Factory No 1 (Spitzer bullets)
2Unknown manufacturer
2Unknown manufacturer (Round nosed bullets)
3Government Cartridge Factory No 3 (Spitzer bullets)
6Unknown manufacturer
BBirmingham Metal & Munitions Co.
CPCrompton Parkinson Ltd
DDum Dum Arsenal
EEley Brothers
GGreenwood & Batley Ltd
GBGreenwood & Batley Ltd
KKynoch
KNKings Norton Metal Co.
ORoyal Laboratory, Woolwich
NDum Dum North Circuit (Sometimes mirror image. Round nosed Bullets)
NNobel Explosives, Glasgow (Spitzer bullets)
RM.O.S. Factory Radway Green
RWRudge-Whitworth Cycle Co.
SDum Dum South Circuit
URemington UMC

I do hope that you find all the above useful.

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