.303-inch

303

.303-inch ammunition was the standard round adopted by the British in 1889, for both Land and Naval, and subsequently Air, service. Through it’s various iterations, the Mk. VII Ball ammunition was that in service at the time of the introduction of the Mk. I Vickers. The development of the ammunition was then closely linked to the development of the different weapons and the various roles of the Vickers led to various demands for different types of ammunition, including explosive, tracer, armour piercing and many others. These are all covered below.

 Metric (mm)Imperial (in)
Calibre7.7.303
Name:British
Case Type:Rimmed, bottlenecked
Bullet Diameter:7.90 
Case Length:56.1 
Rim Diameter:13.44 
Neck Diameter:8.54 
Shoulder Diameter:  
Base Diameter:11.65 
Total Length:76.7 
Weight:28.6 grammes 
Primer:Berdan
Year Introduced:1888
Also known as:
  • .303 Lee Metford
  • .303 Lee Enfield
  • .303 Vickers
  • .303 Bren
  • 7.7x56R
  • 7.7mm Breda
  • 7.7mm Type 89
  • 7.7mm Patrone S 272(e)
  • DWM 371, 453

Variants

One of the variations across all types of ammunition is the propellant change from cordite to nitrocellulose. This is indicated by the letter “Z” as part of the nomenclature. In March 1940, Army Council Instruction 231 was issued and it was authorised that this would be omitted from the stamping on the base of the cartridge to facilitate manufacture; however, it remained on boxes and labels.

Ball

Mark No.ApprovedPropellantPrimerBullet (grains)Envelope materialCannelureHeadstamp includesRemarks
71910CorditeBerdan160Cupro NickelNone“VII”Pointed bullet (as opposed to round nosed bullet of Mk. VI)
71910CorditeBerdan174Cupro Nickel, Cupro Nickel Clad Steel, Gilding Metal, Gilding Metal Clad SteelOne“VII” or “7”Pointed bullet
7z1916NitrocelluloseBerdan174Cupro Nickel, Cupro Nickel Clad Steel, Gilding Metal, Gilding Metal Clad SteelOne“VIIz” or “7z”Pointed bullet
8z1916NitrocelluloseBerdan175Cupro Nickel, Gilding MetalOne“VIIIz” or “8z”Pointed bullet with boattail

As of early 1942, Ball ammunition had a purple annulus.

Cartridge, SA, Ball, .303-inch, Mk. VII (Mk. 7)

First approved in March, 1910, so was the variant in service at the time the Vickers was adopted. The previous variant, the Mk. VI, was in service with the Maxim but the Vickers was not chambered for it. A number of early manuals make reference to the Mk. VI and comparison with the Mk. VII.

It was approved for Land and Naval service in November, 1910, and extended to Air Service in May, 1919 (although likely to have been used extensively before this date).

It used a cordite propellant. It was originally loaded with one glazedboard disc but this was substituted, in 1933, for strawboard to minimise the danger of fired wads to aircraft armed with .303-inch machine guns.

The muzzle-velocity was 2440 feet per second, with 19½ tons per square inch chamber pressure.

One of the major-issues for aircraft use of the Vickers, by the Royal Flying Corps and Royal Air Force, was the quality of ammunition. A special ‘purple label’ ammunition was issued for practice. They also produced a ‘reduced charge’ variant (Cartridge, SA, Ball, .303-inch, NC, Mark VII.z.RC) to simulate a No. 1 stoppage in training. It was introduced in September, 1918, and marked with a blue band 1-inch wide.

This was marked with a black-coloured annulus before 3rd September, 1918, when it was changed to purple.

There were a number of issues with different manufacturers’ ammunition being used in machine guns.

INSPECTION TESTS OF S.A.A. AMMUNITION IN MACHINE GUNS

MUNITIONS DESIGN COMMITTEE SMALL ARMS SECTION Minute (S)42. 25 March 1916.

At a conference held on 10.2.16 it was decided that:-

1. The .303 Maxim gun should be used in the test.

2. The gun should be adjusted so that the lock should go home clear on the .068 cartridge head gauge, and that there should be a check on the 0.69 gauge, the latter being measured by the insertion of a washer or washers in the connecting rod.

3. C.I.S.A. would consider an amendment to paragraph 77 of the .303 Vickers’ Machine Gun Handbook, 1914.

4. C.I.S.A. would give due importance to the decision under (2) in dealing with the repair of machine guns.

D.G.M.D. asks C.I.W. to take the necessary steps to give effect to 1 and 2.

C.S.O.F. reports to D.G.M.D., 8.3.16, that trials have been carried out with O.F. proof of cases. It has always been the custom to prove our own output at a pressure 1 ton higher than service ammunition, to allow for possibly worse conditions in the gun than in our proof gun.

1,000 rounds were fired in the Maxim, with the following clearances and results:-

No. of rounds. Head clearance. Casualties.
1,000 .064″ Nil.
1,000 .0665″ Nil.
1,000 .069″ 2 partial separations.
1,000 .0715″ 1 separation.
6 showing signs.
1,000 .074″ 4 partial separations.
8 showing signs.

A repeat trial was then carried out:-

No. of rounds. Head clearance. Casualties.
1,000 .065″ Nil.
1,000 .068″ 2 showing signs of separation.
1,000 .069″ 1 separation.
6 showing signs.

From these results, which were all carried out with lots of cases which had gone successfully through original proof, it is not clear what clearance should be employed with the ton extra pressure, and it is not thought safe to drop the latter. Tentatively, a clearance such that .067 will just touch will be tried, but until the point is settled we may have difficulty in meeting the new regulations.

C.I.W. reports to D.G.M.D., 13.3.16, that the following four deliveries have, after rejection under the old test, been accepted after re-test under new conditions:-

Kynoch 14.12.15. No. of rounds. Casualties.
1st proof 2,000 9 separations.
4 partial separations.
15 stretched metal.
Re-test 2,500 13 partial separations.
10 stretched metal.
Greenwold and Batley, 16.1.16
1st proof 500 3 burst bases.
1 separation.
Re-test 1,500 4 very slight bursts.
1 partial separation.
Eley, 3.12.15.
1st and 2nd proofs 850 3 separations.
5 partial separations.
1 burst body.
Re-test 1,000 9 partial separations.
Eley, 4.12.15
1st, 2nd and 3rd proofs 1,500 45 separations.
35 partial separations.
34 stretched metal.
1 burst base.
Re-test 1,000 1 separation.
12 partial separations.
33 stretched metal.

D.D.G.(S) informs D.D.G.(E) that he was told by C.I.W. that the trouble with Kynoch’s was due to faulty brass, but that it was now over. That the trouble with Greenwood and Batley was one of manufacture, and this was now also over. That the trouble with Eley’s still existed, being due very largely to faulty brass. He is of the opinion that it is imperative that immediate steps should be taken to see that none but the best material is obtained by, or supplied to, manufacturers of small arms ammunition.

E.M.2 informs D.D.G.(S), 21.3.16, that he is taking this matter up with Eley Bros., and now that supply of brass and cupro-nickel strip for .303 cartridges has been transferred from the Metal Department to his department the points raised in the preceding Minutes will have his special attention. He has written to all S.A.A. manufacturers drawing their attention to the fact thay they are responsible for the testing of all materials used by them.

Referred to the Munitions Design Committee to note.

ACTION TAKEN- Reported to D.D.G.M.D.(S). Noted by the Committee.

Cartridge, SA, Ball, .303-inch, Mk. VIIz (Mk. 7z)

The ‘z’ indicates the use of nitro-cellulose propellant instead of cordite. It was approved for use in May, 1916, for Land Service.

Cartridge, SA, Ball, .303-inch, Mk. VIIIz (Mk. 8z)

The first boat-tailled ammunition was produced to improve accuracy and stability in flight. It was produced for the Vickers and trialled with 20 specially-produced barrels. The Mk. VIIIz was approved for land service in January, 1938, and became the standard ammunition for use in the Vickers in overhead and indirect fire. It was for sole use in the Vickers but could be used in other weapons in exceptional circumstances where reduced muzzle flash was needed. It was the last variant of the .303-inch ball cartridge.

Ammunition details of Cartridges, S.A. Ball, .303-in., Mk. 8z
Muzzle velocityCalculated at 90 ft. – 2440 +- 40 f.p.s
Chamber pressure19 tons per sq. in. (approx.)
CartridgeRimmed.
Colour of annulus – purple.
BulletNose – pointed.
Base – flat.
Form – “boat tail” – streamlined.
Envelope – gilding metal.
Core – lead and antimony 90/10.
Weight – 175 gr. (approx.)
PropellentN.C.
Charge – 36.5 gr.
Extreme range4500 yd.
Figure of merit8 in. at 600 yd.

Whilst the Mark VIIIz ammunition was for the Vickers machine gun, it could be used with other small arms in certain circumstances. The same Army Council Instruction (1464 of November 1940) identified that it mustn’t be used with tracer ammunition in overhead fire.

1464. Use of Mark VII .303-inch S.A.A. and Mark VIIIz .303-inch S.A.A. in barrels of .303-inch Small Arms Weapons (November 1940).

.303″/.22″ Experimental Machine Gun Short Range Practice Ammunition

A necked-down version of the .303-inch Mk. VII case was used to produce a training sub-calibre round that could be used on 30-yard indoor ranges for training purposes. This came with as a set of cartridges and barrel that could be used in a service gun.

Observation

Designed for use in peacetime to provide an artificial means of observing the effect of machine gun fire. In the British Army, its issue was controlled centrally and specific locations and units, associated with machine gun training, were allocated an annual allowance.

The allocation for 1938-39 was set by Army Council Instruction 4 of 1939:

  • Each M.G. battalion at home: 20,000 rounds.
  • Each M.G. troop at home: 100 rounds.
  • Each cavalry armoured car regiment at home: 1,300 [This allowance was removed by Army Council Instruction 64 of 1939].
  • Each cavalry light tank regiment – each recruit and trained man firing the sub-calibre practices detailed in Tank Training, Vol II – Part II, 1936, Table IV or Table IIIB: 40 rounds
  • R. Tank Corps (at home) –
    • Each recruit and trained man firing the sub-calibre practices detailed in Tank Training, Vol II – Part II, 1936, Table IV or Table IIIB: 40 rounds.
    • Gunnery Wing, A.F.V. School – for instruction, trials and demonstrations: 15,500 rounds.
  • Small Arms School, Netheravon Wing – for trials and demonstrations: 1,750 rounds.

If there was any ammunition left at the end of a training year, it had to be used up first as there was a short shelf life for it. The Army Council Instruction included safety instructions that any ‘exudation’ from the bullets needed to be dealt with by placing in a bucket of water and the matter report to the Chief Inspector of Armaments at Royal Arsenal, Woolwich.

As of early 1942, Observing ammunition had a black annulus with code letter O.

Tracer

Tracer ammunition was marked with a red-coloured annulus.

Mark No.ApprovedPropellantPrimerBullet (grains)TypeTrace (yards)Headstamp includesRemarks
Mark I1915CorditeBerdan167Bright75Ball headstamp 
VII T Z1916NitrocelluloseBerdan167Bright800“VII T” or “VII TZ” 
VII G
VII BZ
1916Cordite
Nitrocellulose
Berdan158
168
Bright800“VII G” or “GI”
“VII GZ” or “GIZ”
Later became the G Mark I or G Mark Iz
G Mark II
G Mark IIZ
1937Cordite
Nitrocellulose
Berdan154Bright1000“GII” or “G2”
“G2Z”
 
G Mark III1939CorditeBerdan154Bright800“GIII” 
G Mark IV
G Mark IVZ
1940Cordite
Nitrocellulose
Berdan158Bright / Air / Day550“GIV”
“GIVZ”
White bullet tip
G Mark V
G Mark VZ
1942Cordite
Nitrocellulose
Berdan161Air / Night dark ignition550“GV”
“GVZ”
Grey bullet tip
G Mark VI
G Mark VIZ
1942Cordite
Nitrocellulose
Berdan151Bright / Air / Day550“GVI” or “G6”
“GVIZ”
White bullet tip
G Mark VII1944CorditeBerdan151Delayed Ignition 100 yards1000“G7” 
G Mark 81945CorditeBerdan169Delayed Ignition 100 yards1000“G8”Degraded ogive
PG Mark I
PG Mark IZ
1945Cordite
Nitrocellulose
Berdan154Bright800“PGI”
“PGIZ”
Dark blue band on case

As with other ammunition prior the start of the Second World War, it was allocated to units on an annual basis, according to the weapons training year. For 1939, Army Council Instruction 292 allowed the ‘flame tracer’ .303-inch G Mark II of 5000 rounds to a regular machine gun battalion, 300 rounds for a depot then 14,350 rounds to the Small Arms School, Netheravon Wing.

As of early 1942, Tracer ammunition had a red annulus and code letter ‘G.’

Armour Piercing (A.P.)

Armoured Piercing ammunition was marked with a green-coloured annulus.

Mark No.ApprovedPropellantPrimerBullet (grains)Envelope materialCoreHeadstamp includesRemarks
VII S1915CorditeBerdan174Cupro Nickel33 grain steel tipVII S 
VII P
VII PZ
1916Cordite
Nitrocellulose
Berdan174Cupro Nickel80 grain steelVII P
VII PZ
 
VII F
VII FZ
1916Cordite
Nitrocellulose
Berdan155copper67 grain steelVII F
VII FZ
semi-armour piercing
VII W
VII WZ
1917Cordite
Nitrocellulose
BerdanCupro Nickel93 grain steelVII W or W I
VII WZ or W IZ
Titles changed in 1927 from VII W or VII WZ to W Mk. I or W Mk. I Z 

As of early 1942, Armour Piercing ammunition had a green annulus with code letter W. Semi-Armour Piercing also had a green annulus but code letter F.

Incendiary and Explosive

Note: Not all incendiary and explosive ammunition was suitable for synchronised Vickers Guns; however, it is included in this information for completeness.

Incendiary ammunition was marked with a blue coloured annulus and code letter B. Explosive ammunition was marked with a orange-coloured annulus before the Second World War, when it changed to a black-coloured annulus and code letter R.

Mark No.ApprovedPropellantBullet weight (grains)FillingHeadstamp includedRemarks
VII K (Brock)1916Cordite149Potassium ChlorateBall headstamp, usually 
Buckingham Mk. I1915Cordite170Yellow phosphorousBall headstampRound nosed bullet
Buckingham Mk. 2
Buckingham Mk. 2Z
1916Cordite
Nitrocellulose
137Phosphorous and aluminium powder“VII B”Pointed bullet
Buckingham Mk. 3
Buckingham Mk. 3z
1918Cordite
Nitrocellulose
147Phosphorous and aluminium powder“VII B”Flat tipped bullet
B Mark 4
B Mark 4z
early 1920sCordite
Nitrocellulose
150Phosphorous“B IV”
“B IV Z”
Stepped bullet
B Mark 4 z*c.1940Nitrocellulose154Phosphorous“BZ”Stepped bullet
B Mark 6
B Mark 6z
1939Cordite
Nitrocellulose
157SR 365 (Barium Nitrate)“B VI”
“B VI Z”
Pointed bullet
B Mark 7
B Mark 7z
1941Cordite
Nitrocellulose
177SR 365 (Barium Nitrate)“B VII”
“B VII Z”
Pointed bullet
PSA Mark I1916Cordite155NitroglycerineBall headstampCopper warheard
PSA Mark 2
PSA Mark 2z
1917
1918
Cordite
Nitrocellulose
167Nitroglycerine“VII AA”Copper warhead
RTS Mark I1917  NitroglycerineNo special markingsCopper warhead
RTS Mark 2z1917Nitrocellulose168NitroglycerineNo special markingsCopper warhead
O Mark I1934Cordite174Phosphorous“O I” 

Blank Ammunition

Blank ammunition was used with the Blank Firing Attachments. The use of bulleted or long-necked blank was necessary in the Vickers to avoid No. 3 stoppages. The use of ‘short’ blank was officially restricted but it appears that the availablity of the Mk. V blank for all other weapons meant that it was often used in the Vickers, possibly with amendments to the feedblock.

Mark No.ApprovedPrimerCaseTypeRemarks
Mark 5 Cordite (also nitrocellulose)1894BerdanBall typeCrimped 
Mark 6 Cordite, mock bullet1901BerdanBall type, crimped with a mock bullet Case blackened with brass mock bullet
L Mark 7, wood bulleted1939BerdanBall typeUncrimpedYellow wood bullet
L Mark 9 Z1955BerdanBall typeCrimped 
Machine gun Mark I1914BerdanSolid drawnShort body (heavily bottlenecked) 
Variants of blank ammunition

In the British Army, at the start of the Second World War, blank ammunition was issued with an annual allowance for the weapons training year. This was done on a Command-by-Command basis as shown in the list below (for 1938-39) from Army Council Instruction 65 of 1939:

  • Aldershot Command: Regular Army 1,200,000 rounds.
  • Eastern Command: Regular Army 831,000 rounds; Territorial Army 200,000 rounds.
  • Northern Command: Regular Army 600,000 rounds; Territorial Army 260,000 rounds.
  • Scottish Command: Regular Army 125,000 rounds; Territorial Army 140,000 rounds.
  • Southern Command: Regular Army 850,000 rounds; Territorial Army 120,000 rounds.
  • Western Command: Regular Army 60,000 rounds; Territorial Army 275,000 rounds.
  • London District: Regular Army 400,000 rounds; Territorial Army 140,000 rounds.
  • Northern Ireland District: 110,000 rounds.
  • Guernsey and Alderney District: 20,000 rounds.
  • Egypt and Palestine: 900,000 rounds.
  • The Sudan: 100,000 rounds.
  • Bermuda: 7,000 rounds.
  • China: 445,000 rounds.
  • Gibraltar: 40,000 rounds.
  • Jamaica: 30,000 rounds.
  • Malta: 130,000 rounds.
  • Malaya: 170,000 rounds.

These would then be used by the General Officers’ Commanding-in-Chief as they saw fit in their areas, including the recruit training that was taking place at depots. There were also specific allocations for training establishments. The machine gun related allowances were:

A note allowed for the issue of the blank firing attachments for the Vickers to Territorial Army units as needed.

Drill and Inspectors

Note: Early cartridges Marks, related to the Mk. 6 Ball ammunition, have been omitted from the list.

Mark No.ApprovedDescription
Dummy Drill Mark 41910Brass case pierced with holes. Pointed wood bullet.
Dummy Drill Mark 51917Reject service case, blackened, pierced with holes. Mark 7 ball bullet.
Dummy Drill Mark 61917White metal case with three flutes. Solid bullet or Mark 7 ball bullet.
Drill D Mark 71932Tinned case with three flutes. Metal clad bullet with aluminium core.
Drill D Mark 81941Brass case with three thin flutes or holes. Red wood bullet and distance piece.
Drill D Mark 91943Brass or chromed case with three thin flutes or holes. Metal clad wooden bullet.
Drill D Mark 101954Chromed brass case with three flutes. Mark 7 ball bullet.
Drill D 1942 Canadian1942Chromed brass case with three flutes. Mark 7 ball bullet.
Inspectors Dummy Mark 41911Tinned brass case, service bullet. Weighted to approximate to Cordite ball Mark 7.
Inspectors U Mark 51918White metal or chromed case, pointed bullets of various forms.
Machine gun Dummy Mark 21910Solid steel dummy cartridge with pointed nose, weighted to approximate to cordite ball.

Countries using this calibre


Sources