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 type | Rimmed, bottleneck |
Bullet diameter | 7.92 mm (0.312 in) |
Neck diameter | 8.64 mm (0.340 in) |
Shoulder diameter | 10.19 mm (0.401 in) |
Base diameter | 11.68 mm (0.460 in) |
Rim diameter | 13.72 mm (0.540 in) |
Rim thickness | 1.63 mm (0.064 in) |
Case length | 56.44 mm (2.222 in) |
Overall length | 78.11 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.
COLOUR | LOAD |
Purple | Ball and short range practice ball |
Red | Tracer (also some explosive rounds) |
Green | Armour-piercing and semi armour-piercing |
Blue | Incendiary |
Black | Explosive and observation |
Yellow | Proof and standard |
Orange | Some explosive rounds |
Clear | Blank |
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
COLOUR | LOAD |
White | Tracer G Mark IV and VI (daytime tracer) |
Grey | Tracer G Mark V (night-time tracer) |
Red | Canadian tracer G Mark II and some British G Mark II |
Blue | Incendiary B Mark VII and VIIz |
Green | Armour-Piercing W Mark Iz, but only used for export contracts, not British service |
Black | Observation Mark I |
Orange/Yellow | Believed 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.
Marking | Cartridge |
Top half blackened, open neck | Rifle grenade H Mark I |
Whole case blackened, open neck | Rifle grenade H Mark II |
Top and bottom thirds blackened, rosette crimp | Rifle grenade H Mark 4 & 4z |
Bottom half blackened, rosette crimp | Rifle grenade H Mark 7z |
Bottom half blackened, open neck | Discharger smoke generator E I.T |
Whole case blackened, brass mock bullet | Blank Mark VI (pre 1907) |
Whole case blackened, rosette crimp | Blank Mark VI (post 1907) |
Top third blackened, bulleted | Short range practice |
Bottom third blackened, bulleted | Match ammunition |
Top and bottom thirds blackened, bulleted | Match ammunition |







Some 303 drill rounds were also blackened.
Marking | Cartridge type |
Blackened case and bullet, 4 holes drilled in cartridge case | Dummy drill Mark V (WW1) |
Blackened case and bullet, six narrow flutes extending from shoulder | Drill round, produced by Colonial Ammunition Company, New Zealand during WW2 |
Blackened cartridge case and bullet | Drill 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 I | Empty brass case, tinned, no cap, coreless bullet |
Dummy Drill Mark II | Empty brass case, tinned, no cap, coreless bullet, case coned and indented to secure bullet |
Dummy Drill Mark III | Plain (Pre 1907) or red (post 1907) round nosed wooden bullet. Case usually brass but was tinned prior to 1905. |
Dummy Drill D Mark VI | Chromed or cupro-nickel case, jacketed spitzer bullet, three vertical flutes, (usually painted red) |
Drill D Mark VII & VIIN | Cupro-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 IX | WW2 expedient. Can be found as plain brass or tinned/chromed cases |
Drill D Mark 10 | Chromed case with three red flutes. Gilding metal jacketed bullet with empty cap chamber, sometimes painted red |
Drill D 1942 Canadian pattern | Chromed case with three flutes |
Dummy Inspectors Mark I | Tinned brass case, filled with coal dust, round nosed bullet |
Dummy Inspectors Mark II | Tinned brass case, filled with coal dust, round nosed bullet |
Dummy Inspectors Mark III | Tinned brass case, filled with coal dust, round nosed bullet |
Dummy Inspectors Mark IV | Tinned brass case, filled with coal dust, pointed bullet |
Dummy Inspectors U Mark 5 or V | White 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.
Suffix | Load |
A.A | Pomeroy incendiary P.S.A. Mark II |
B | Buckingham incendiary |
F | Kings Norton Semi-Armour Piercing |
G | S.P.G. Tracer |
K | Brock incendiary |
P | Kynoch Armour-Piercing |
R.C. | Reduced Charge |
R.T.S. | Explosive (Richard Threlfall & Son) |
R.T.T. | Explosive (Richard Threlfall Todhunter) |
S | Royal Laboratory Armour Piercing |
T | S.P.K. ‘Sparklet’ tracer |
W | Armour Piercing |
Y | Pomeroy 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.
Prefix | Load |
B | Incendiary |
D | Drill |
E | Smoke Generator Discharger |
F | Semi Armour Piercing |
G | Tracer |
H | Rifle Grenade |
L | Blank |
O | Observation |
P | Practice |
Q | Proof |
R | Explosive |
U | Inspector’s Dummy |
W | Armour 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,
Marking | Propellant |
Undated, no code | Black powder |
Undated, code ‘C’ | Cordite |
Dated, no code | Cordite |
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 .
Code | Manufacturer | Period Used |
![]() | Ministry of Supply Factory, Radway Green, Cheshire | 1940-41 |
![]() ![]() | Ministry of Supply Factory, Spennymoor, Yorks | 1940-42 |
B | Birmingham Metal and Munitions Co. Ltd | 1892-1918 |
BE | Ministry of Supply Factory, Blackpole, Worcs (cases supplied by RG) | 1939-45 |
B E | Ministry of Supply Factory, Blackpole, Worcs (cases supplied by K4) | 1939-45 |
B![]() | Ministry of Supply Factory, Blackpole, Worcs, (cases supplied by own factory) | 1939-45 |
BM | British Munitions Company | 1890s |
BPD | Bombrini Parodi Delfino | 1980s |
CP | Crompton Parkinson, Doncaster, Yorks | 1939-45 |
C-P | Crompton Parkinson, Guisley, Yorks | 1939-45 |
E | Eley Brothers | 1890s-1918 |
E B | Eley Brothers | 1889 |
G | Greenwood & Batley Ltd, Leeds, Yorks | 1890-1920 |
GA | Grenfell & Accles Ltd, Birmingham | 1890s |
GB | Greenwood & Batley Ltd, Leeds, Yorks | 1890s-1958 |
H![]() | Ministry of Supply Factory, Hirwaun, South Wales | 1939-45 |
HXP | Greek Powder & Cartridge Company | 1980s |
J | Birmingham Metals and Munitions Co. Ltd., Waltham, Essex | 1914-1918 |
K | George Kynoch Ltd, Birmingham | 1890-1920 |
K | Kynoch Division of ICI Ltd, Birmingham | 1920-76 |
K2 | Kynoch, ICI, Standish, Lancs | 1939-45 |
K4 | Kynoch ICI, Yeading, Middlesex | 1939-45 |
K5 | Kynoch ICI, Kidderminster, Worcs | 1939-45 |
KN | Kings Norton Metal Co. | 1890-1920 |
L | Lorenz Ammunition Ordnance Co., Millwall, London | 1890s |
M | Morris Patent Tube Co. Ltd, Birmingham | 1890s |
M | Nobel Explosives Ltd., Glasgow | 1914-18 |
N | Nobel Explosives Ltd., Glasgow | 1914-18 |
RG | Ministry of Supply Factory (later Royal Ordnance Factory), Radway Green, Cheshire | 1942-73 |
R![]() | Royal Laboratory, Woolwich | 1888-1954 |
R![]() | Royal Laboratory, Cartridge Factory No 3, Woolwich | 1917-18 |
R(Date)L | Royal Laboratory, Cartridge Factory No 5, Woolwich | 1915-18 |
RW | Rudge Whitworth Cycle Co., Nottingham | 1939-45 |
SR | Ministry of Supply Factory,Spennymoor, Yorks | 1939-45 |



















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.

There is a subtle difference between Indian and British headstamps, with the Indian ones carrying the month of manufacture, as well as the year.
Code | Factory | Date |
D | Dum Dum Arsenal, Calcutta | 1895-1913 |
DF | Dum Dum Arsenal, Calcutta | 1895-1913 |
K | Kirkee Arsenal | 1895-1914 |
K![]() | Kirkee Arsenal | 1895-1960 |
N | Dum Dum Arsenal, Northern Circuit | 1895-1914 |
OK | Ordnance Factory, Khamaria, Jubbulpore | 1943-1970s |
P.O.F. | Pakistan Ordnance Factory | 1947 onwards |
S | Kirkee Arsenal, Southern Circuit | 1895-1913 |
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.

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.
Code | Manufacturer | Period Used |
D | Dominion Cartridge Company | 1918 |
DA | Dominion Arsenal, Quebec | Pre 1940 and post 1945 |
DAC (The C is as above) | Dominion Arsenal, Quebec | 1920-45 |
DAL | Dominion Arsenal, Lindsey | 1917-21 |
DC | Dominion Cartridge Company | 1895-1918 |
D![]() | Dominion Cartridge Factory (Dominion Arsenal post 1900) | 1890s |
DCA (The C as above) | Dominion Arsenal, Quebec | 1935 |
DI | Defence Industries Ltd. | 1940-45 |
LAC (The C as above) | Dominion Arsenal, Lindsey | 1914-17 |
RR Co | Ross Rifle Co., Quebec | 1915-17 |





Australia & New Zealand
A![]() | Small Arms Ammunition Company, Footscray | Jan 1924- Feb 1925 |
CAC | Colonial Ammunition Company, Footscray | 1890-1920 |
CAC | Colonial Ammunition Company, Auckland | 1898-1950s |
![]() | SAAF Footscray | Mar 1925 – April 1926 |
F | SAAF Footscray | 1926 |
MF | SAAF No 1 Footscray | May 1926-62 |
MF1 | SAAF No 1 Footscray | 1940 |
MF2 | SAAF No 2 Footscray | 1940 |
MG | SAAF No 2 Footscray | 1940-48 |
MH | SAAF No 3 Hendon | 1940-45 |
MJ | SAAF No 4 Hendon | 1941-44 |
MQ | SAAF No 5 & 6 Rocklea | 1942-43 |
MS | Salisbury Explosives Factory | 1944 |
MW | SAAF No 7 Welshpool | 1942-45 |
SAAF | SAAF Footscray | 1921-23 |




South Africa
Code | Manufacturer | Date Used |
A | Armscor | 1975-80 |
PMP | Pretoria Metal Pressings Pty, Pretoria | 1965-75 |
SAM | South African Mint, Pretoria | 1961-65 |
U | South African Mint, Pretoria | 1938-42 and 1945-61 |
U | South African Mint, Kimberley | 1941 |
U ![]() | South African Mint, Kimberley | 1942-45 |



USA
US companies produced millions of rounds of 303 for both World Wars. Virtually all the ammunition produced was standard ball ammunition.
Code | Manufacturer | Date Used |
H | National Brass and Copper Tube Co., Hastings, NY | 1916 |
P | Peters Cartridge Co., Kings Mills, Ohio | 1915-17 |
PC | Peters Cartridge Co., Kings Mills, Ohio | 1940 |
RA | Remington Arms Co., Bridgeport, Connecticut | 1915-17 |
U | Remington Arms Co., Bridgeport, Connecticut | 1915 |
US | United States Cartridge Co., Lowell, Massachusetts | 1915-17 |
W | Winchester Repeating Arms Co., New Haven, Connecticut | 1914-17 |
WCC | Western Cartridge Co., East Alton, NY | 1940-43 |
WRA | Winchester Repeating Arms Co., New Haven, Connecticut | 1940-43 |



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.
Code | Manufacturer |
G | Greenwood & Batley |
K | ICI Kynoch |
R | M.o.S.F. Radway Green |
S | M.o.S.F. Spennymoor (the ‘S’ was usually a mirror image) |
2 | ICI Kynoch, Standish |
4 | ICI Kynoch, Yeading |
5 | ICI 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;
Code | Manufacturer |
![]() | Royal Laboratory, Woolwich (also found with a * or other mark beneath the arrow) |
1 | Unknown manufacturer (Round nosed bullets) |
1 | Government Cartridge Factory No 1 (Spitzer bullets) |
2 | Unknown manufacturer |
2 | Unknown manufacturer (Round nosed bullets) |
3 | Government Cartridge Factory No 3 (Spitzer bullets) |
6 | Unknown manufacturer |
B | Birmingham Metal & Munitions Co. |
CP | Crompton Parkinson Ltd |
D | Dum Dum Arsenal |
E | Eley Brothers |
G | Greenwood & Batley Ltd |
GB | Greenwood & Batley Ltd |
K | Kynoch |
KN | Kings Norton Metal Co. |
O | Royal Laboratory, Woolwich |
N | Dum Dum North Circuit (Sometimes mirror image. Round nosed Bullets) |
N | Nobel Explosives, Glasgow (Spitzer bullets) |
R | M.O.S. Factory Radway Green |
RW | Rudge-Whitworth Cycle Co. |
S | Dum Dum South Circuit |
U | Remington UMC |
I do hope that you find all the above useful.

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I bought some .303 this weekend at the gun show. The seller said it was Indian manufacture. On the headstand it has three markings: KF 73 7 indicating it’s made at the Kirkee Arsenal, but examples of that ammo I’ve seen show a Indian ordnance mark between the K and the F, and the seven as VII instead of a 7, and instead of the year only (mine: 73) it has month-year. This web site indicates the factory only produced ammo from 1895-1960. Could this still be a Kirkee Arsenal cartridge?
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Hi Clinton. Please use the contact page to send me an email and, when I reply, you’ll be able to send me some pics.
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