7.62mm NATO Proof, Armour Piercing & Grenade
Proof
Prior to the formal approval of a 7.62mm Proof round, the earliest rounds used to proof the first L1A1 rifles made at RSAF Enfield were made with standard L2A1 ball components and headstamped "RG 55 7.62 A1". To achieve proof pressure Belgian nitrocellulose powder was used. The cartridges were identified by a red bullet tip.
An experimental proof round exists which is a predecessor of the L4A1 proof round. It is made using normal ball components but the case is copper washed for identification. The case is unheadstamped.
Left: "RG 55 7.62 A1" early proof. Right: unheadstamped copper washed proof round.
Proof L4A1
"Round 7.62mm Proof L4A1" was approved to design S1/12246/GF/1342 in 1956.
The case was the standard design (QV47) and was originally copper washed for identification. Cases were specially chosen for correct head hardness. The Berdan primer was ringed in and had a yellow annulus. The headstamp included the code "L4A1". In 1981 the practice of copper washing the cases ceased and was replaced by milling the rim to give a serrated edge for identification. Later the milling of the rim was also omitted and the headstamp became the only identification.
The bullet was the standard L2A2 ball bullet of 9.33g (144 grains).
The charge was 2.85g (44 grains) of nitrocellulose.
Initially pressure was set between 27 and 29 tsi (4170 to 4480 bar) but in November 1990 this was reduced to 26 to 28 tsi (4016 to 4324 bar)
Left: copper washed case, right; milled rim case.
All L4A1 proof rounds were made by Radway Green, but ICI Kynoch also manufactured proof rounds which were identified by a copper washed case and a purple stripe on the case head.
In 1962 two experimental proof cases were developed with thicker case walls and increased weight. One type was identified by a white paint blob on the head and the other by a black blob. Neither type were adopted for service.
Armour Piercing
There has been no Land Service requirement for 7.62mm armour piercing ammunition, but the Royal Navy has a requirement for sinking mines brought to the surface from sweeping or that have broken loose from their moorings.
ICI Kynoch supplied the Royal Navy with AP ammunition in the early 1960s using British cases loaded with bullets fitted with AP cores from Belgium. The cases were headstamped "K60 L2A2" and the bullets were black tipped for identification. A later batch were loaded with Dutch AP bullets.
There were two British designs of AP bullet by Kynoch dating from the early 1960s but neither were adopted for service. Subsequent requirements for AP ammunition has been met by importing Belgian P.80 AP rounds from FN.
Rifle Grenade
Prior to the formal adoption of a grenade cartridge there were two pre-production types manufactured in small numbers.
The first appeared in 1953 and consisted of a plain brass case without any blackening, left open at the neck. The charge was held in the case by a wad in the neck sealed with shellac. Early ball cases were used and the headstamp was "RG 53".
The second type, dating from 1954, utilised a rosette crimp case like the service L1A1 but had the top half blackened. The headstamp was also unusual in that it was the reverse of the normal arrangement,being "54 RG".
L1A1
"Cartridge 7.62mm Rifle Grenade L1A1" was approved to design D6/L/1291/GF/140 in August 1954 and shown in Lists of Changes Paragraph C.6519 dated February 1955. It was intended for firing the No.94 Energa anti-tank grenade from the L1A1 rifle.
The case was that of the L2A1 ball round with the mouth closed by a short rosette crimp. The primers were ringed in and the lower half of the case was chemically blackened. The headstamp included the code "L1A1"
The propellant charge was about 2g ( 30.8 grains) of nitrocellulose NRN10.
The L1A1 was only manufactured by Radway Green.
An experimental version of the L1A1 also exists which is uncrimped. In all other respects it is similar to the service L1A1 and has the lower half chemically blackened. the headstamp is "RG 55 7.62 L1A1". The case mouth is sealed with a shellac covered disc.
The reason for this variation is not known.
Right: Uncrimped version of L1A1.
L1A2
"Cartridge 7.62mm Rifle Grenade L1A2" was approved to design S1/12249/GF/1344 in February 1956 and shown in Lists of Changes Paragraph C.7607 dated October 1956. It was intended for firing the No.94 Energa anti-tank grenade from the L1A1 rifle.
The case was that of the L2A2 ball round with the mouth closed by a short rosette crimp. The primers were ringed in and the lower half of the case was chemically blackened. The headstamp included the code "L1A2"
The propellant charge was about 2.5g ( 38.5 grains) of nitrocellulose NRN10. A celluloid cup was fitted to the neck of the case and secured with shellac.
It was manufactured by both Radway Green and ICI Kynoch.