The serial number of a gun was allocated by the manufacturer to individually identify the gun so that a record could be kept of it throughout its life and service. Generally the number is stamped or inscribed on the top of the water jacket (or cooling jacket in the case of aircraft guns). Other places noticed on some examples are on the base of the cross-piece, the bottom slide, the top cover (front and back) and the mounting blocks.
Feedblock marked to a ‘K’ series Vickers Mk I produced at Vickers Ltd., Erith. 
The two serial numbers which are marked as being on feedblocks, were in fact on the same feedblock which indicates that the feedblock was first part of the ‘K’ series guns but when mass refurbishment of guns took place, it was reallocated to a gun with serial number ‘8304’ which would, at first glance, indicate it was an Australian-manufactured gun; however, it is relatively common to find components marked with just the numerals of a serial number and not the letters.
Whilst the main component to be marked with a serial number is the gun itself, some replacement parts were also serialised: principally the lock and the barrel. The lock was usually marked in three locations: on the base of the lock casing, the side levers and the extractor. A sample of 84 extractors received by the VMGCRA gave us an opportunity to examine them for all markings. We found a number of example serial numbers among them – they are shown in the slideshow below. It is possible that some are marked to the guns upon which they were placed; however, the T and U serial numbers are known to be for replacement locks.
Tracing serial numbers
In order to identify the approximate period of the manufacture of a gun, it is possible to use the serial number prefix (i.e. the letter). This may also give an indication of the location of manufacture – although some other information is needed to provide certainty. The following table will be of use.
| Prefix | Type | Period | Location Built |
| A | Mk. I | 1916 – 1918 | Vickers Ltd., Erith, Kent, UK |
| A | Mk. II | 1918 – 1919 | Vickers Ltd., Crayford, Kent, UK |
| A | Mk. V RH Mk. V LH | 1935 – 1941 | Small Arms Factory, Lithgow, Australia |
| A | M1918 | 1917 – 1918 | Colt PFA Mfg Co, Hartford, Conneticut, USA |
| A | M/939 | 1939 | Fabrico de Braco de Prata, Portugal |
| A | Commercial | 1932 – 1933 | Vickers Armstrongs Crayford, Kent, UK |
| B | Mk. I | 1917 – 1918 | Vickers Ltd., Erith, Kent, UK |
| B | Mk. I | 1944 – 1945 | Small Arms Factory, Lithgow, Australia |
| B | Commercial | 1933 – 1934 | Vickers Armstrongs Crayford, Kent, UK |
| C | Mk. I | 1916 – 1918 | Vickers Limited, Crayford, Kent, UK |
| C | Commercial | 1935 – 1936 | Vickers Armstrongs Crayford, Kent, UK |
| D | Mk. I | 1918 | Vickers Limited, Crayford, Kent, UK |
| D | Commercial | 1936 – 1937 | Vickers Armstrongs Crayford, Kent, UK |
| E | Commercial | 1937 – 1938 | Vickers Armstrongs Crayford, Kent, UK |
| ET | Mk. I | c.1942 | Vickers Armstrongs Crayford, Kent, UK |
| F | Mk. I | 1918 | Vickers Limited, Crayford, Kent, UK |
| F | Commercial | 1939 | Vickers Armstrongs Crayford, Kent, UK |
| G | Mk. I | 1918 | Vickers Limited, Crayford, Kent, UK |
| G | .5-inch Mk. I .5-inch Mk. II .5-inch Mk. IV .5-inch Mk. V | 1932 – 1940 | Vickers Armstrongs Crayford, Kent, UK |
| H | Mk. I | 1918-1919 | Vickers Limited, Erith, Kent, UK |
| IK | Mk. I | c.1942 | Vickers Armstrongs Crayford, Kent, UK |
| K | Mk. I | 1918 – 1919 | Vickers Limited, Erith, Kent, UK |
| L | Mk. I | 1911 – 1916 | Vickers Limited, Erith, Kent, UK |
| N | M/930 | 1930 | Fabrico de Braco de Prata, Portugal |
| N | Nepalese Special | 1936 | Colt PFA Mfg Co, Hartford, Conneticut, USA / Grimaud |
| S | .5-inch Mk. III | 1932 – 1945 | Vickers Armstrongs Crayford, Kent, UK |
| T | Mk. XXI | 1941 – 1944 | Small Arms Factory, Lithgow, Australia |
| V | Mk. I | 1939 – 1944 | Vickers Armstrongs Crayford, Kent, UK |
| W | Mk. I | 1943 – 1945 | Vickers Armstrongs Crayford, Kent, UK |
| — | M1915 | 1915 – 1918 | Colt PFA Mfg Co, Hartford, Conneticut, USA |
| — | Mk. I | 1933 – 1945 | Small Arms Factory, Lithgow, Australia |
| — | Commercial | 1908 – 1931 | Vickers Sons & Maxim (then Vickers Limited), Erith, Kent, UK |
Production dates
- No prefix
- Mk. I
- Small Arms Factory, Lithgow, Australia
- 1 to 697: 3 May 1929 to 2 September 1939
- 697 to 1432: 3 September 1939 to 30 June 1940
- 1433 to 3223: 1 July 1940 to 30 June 1941
- 3223 to 5971: 1 July 1941 to 30 June 1942
- 5972 to 8650: 1 July 1942 to 30 June 1943
- 8651 to 9999: 1 July 1943 to 30 June 1944
- Small Arms Factory, Lithgow, Australia
- Mk. I
- B prefix
- Mk I
- Small Arms Factory, Lithgow, Australia
- Mk I
It is very rare to be able to trace the service history of a specific gun. The serial numbers were rarely recorded at all, yet some may come up in war diaries or unit records – this is by far the exception rather than the rule.
