7.62mm NATO Tracer
British tracer development started in 1954 both at Radway Green and Kynoch with the latter diong much of the work as they had the greater experience in tracer design.
The first tracer bullet was to design D6/L/1379/GF/149 in 1954 and was a dark ignition tracer that traced to 1000 metres. The trajectory closely matched the ball round at 600 metres. The cases were unheadstamped and there was no red primer annulus or tip colour, but the bullet had a knurled cannelure above the case mouth as identification. Different tracer compositions were tried including R17A (magnesium and strontium nitrate), RD1177 (potassium 2;4 dinitrophenate and barium peroxide) and SR390 (magnesium, strontium nitrate and strontium peroxide). Some subsequent manufacture that year was unheadstamped but had red bullet tips
Another 1954 design to D6/L/1400/GF/149 was based on a French tracer design with a long internal tracer canister and was known in the UK as the "Continental" tracer.
The difficulties with tracer design centered on the facts that the longer flat based tracer bullet reduced the powder capacity of the case and the propellant used for the ball round was unsuited to tracer.
A very great deal of work was done by both RG and Kynoch in the period 1955 to 1959 with experimental tracers being loaded on ball cases but with red primer annuli and various coloured bullet tips.
The first tracer was not approved for service until 1959.
Tracer L5A1
"Round 7.62mm Tracer L5A1" was approved to design P3/18790/GF/383 in September 1959 and shown in Lists of Changes Paragraph C.9770 dated February 1961.
The case was that of the L2A2 ball round but with a red primer annulus. The headstamp included "L5A1" but the calibre was not included and neither was the NATO symbol as the L5A1 did not meet the NATO specification fully.
The bullet was flat based with a 3.939 inch radius ogive and a GMCS envelope. It had one seating cannelure with a knurled ring above for identification and a red tip. The front core was of 98/2 lead antimony alloy with the tracer composition in a gilding metal canister closed with a brass washer. It weighed 8.75g (135 grains).
It was a dark ignition tracer with a bright red trace to 1000 metres. Two different tracer compositions were used in the L5A1, the first being 0.52g (8 grains) of R17A composition with 0.13g (3.5 grains) of SR462 priming composition and the second 0.62g (17 grains) of SR390 tracing composition with 5% talc and 0.06g (0.93 grains) of SR867 priming composition.
The propellant was 2.5g (38.5 grains) of nitrocellulose and observed velosity was 780 metres/second (2560 fps)
Tracer L5A2
"Round 7.62mm Tracer L5A2" was developed in 1960 in response for a requirement for a bright ignition tracer for use in jungle or hevy vegetation and was to design P3/19174/GF/383.
The case was as for the L5A1 and had either a Kynoch L5A1 headstamp or no headstamp.
For the bright ignition SR126 proming composition was used with graphite added and the main tracing composition was SR390A. The bulllet had a red tip and weighed 8.75g (135 grains).
It is believed that it was only made by ICI Kynoch and most stocks were used in trials and calibration work.
Tracer L5A3
"Round 7.62mm Tracer L5A3" was approved to design DD/E/22302/GF/383 in May 1962 and shown in Lists of Changes Paragraph D.200 dated December 1963. It replaced the L5A1 which had never been entirely satisfactory.
The case was to the normal design with a Berdan primer and a red primer annulus. The headstamp initially included "L5A3" without the NATO symbol, but this was included from about 1966 when the round met MATO specifications. From 1976 the "L" number was omitted from the headstamp to give a three position "universal" headstamp but the four position headstamp with "L5A3" was reinstated in 1994..
The bullet was similar to the L5A1 with a red tip and a knurled identification cannelure above the case mouth. The same tracing compositions were used but two additional main compositions were authorised, SR607 and RT11.
The L5A3 was a dark ignition tracer that traced bright red to 1000 metres.
The Propellant was about 2.66g (41 grains) of NRN nitrocellulose and the observed velocity was 799 metres/sec (2620 fps).
Tracer L5A4
"Round 7.62mm Tracer L5A4" was to design DD/E/24718/GF/383 and made in limited quantities in 1968.
The bullet was similar to the L5A3 and the main tracer composition was either SR607 or RT11. Both used 0.06 (0.93 grains) of SR867 priming composition.
In other respects it was similar to the L5A3 except the propellant was 2.85g (44 grains) of ball powder.
Tracer L5A5
"Round 7.62mm Tracer L5A5" was manufactured to design DD/E/24798/GF/383 in limited quantities in the 1970s. During development it carried the title XL5E5.
It is believed that the L5A5 had modified ballistics to meet the NATO specification for barrel gas port pressure but was in all other respects similar to the L5A3 tracer.
Other tracers
During this period two other tracers were purchased "off the shelf" for British use but were not formally awarded British "L" nomenclature. These were:
"Round 7.62mm Tracer M62" from Raufoss in Norway. This was the Norwegian version of the American M62 tracer and was identified by an orange bullet tip. It is a dark ignition tracer.
"Round 7.62mm Tracer" from FNM in Portugal. This had a red bullet tip and was dark ignition.
Neither round was specially marked for British service and they bore their normal native headstamps
In addition to these"L" numbers were allocated to a number of foreign tracer rounds but it is believed none were actually ordered or imported.
"Round 7.62mm Tracer L23A1" was allocated to FFV, Sweden (Drawing reference QV131GF)
"Round 7.62mm Tracer L24A1" was allocated to Hirtenberger, Austria (Drawing reference QV132GF)
"Round 7.62mm Tracer L25A1" was allocated to SFm, France (Drawing reference QV1331GF)
"Round 7.62mm Tracer L26A1" was allocated to FN, Belgium (Drawing reference QV134GF)
"Round 7.62mm Tracer L27A1" was allocated to FNM, Portugal (Drawing reference QV135GF)
"Round 7.62mm Tracer L28A1" was allocated to Raufoss, Norway (Drawing reference QV136GF)
"Round 7.62mm Tracer L29A1" was allocated to MEN, Germany (Drawing reference QV139GF)
Tracer L45A1
"Round 7.62mm Tracer L45A1" is the current issue tracer round manufactured by Radway Green.
Some rounds have the normal red primer annulus but most have a green primer annulus and the headstamp includes "L45A1". Why a green primer annulus, which is also used on some recent ball rounds, is being used is not known.
The bullet has a red tip and a knurled identification cannelure above the case mouth. It is a dark ignition tracer but no further details are known.
Tracer L47A1
"Round 7.62mm Tracer L47A1" is manufactured on British contract by CBC Brazil, although since they now own MEN in Germany it may well be manufactured there.
The bullet has a red tip and a knurled identification cannelure above the case mouth. It is a dark ignition tracer but no further details are known.
Tracer L56A1
"Round 7.62mm Tracer L56A1" is a dim tracer designed for night use and is visible only to infra red night vision devices. No further details are known.
Experimental Tracer
In addition to the above, a great deal of work was carried out on experimental tracers, mainly to find a better ballistic match with ball ammunition. Details are given here.