The 4.85mm cartridge.


In the early 80's The North Atlantic Treaty Organisation (NATO) had decided to abandon the 7.62x51 round in favor of a new ultra small round for future use. The new round would be selected after several tests conducted by NATO. The United Kingdom was entering these tests with a new developed cartridge, the 4.85mm. around this cartridge they created a bullpup rifle the I.W. (individual weapon) and a light machine gun, the L.S.W. (light support weapon) A wide range of different types of the 4.85 cartridges were made, but only the ball XL1E1 rounds and the tracer XL2E1 rounds were used in the NATO tests. (see images)


Finally the Belgium .223 ss109 round was chosen as the future cartridge for NATO and the 4.85 was abandoned. 

The different types of the 4.85 mm:


The first ball cartridges were 4.85x44mm with 56 grain bullets. They had a lead / antimony core (90/10 and 98/2). There were two types of envelopes used (CNCS and GMCS). The shape of the bullet was taken from the experimental 6.35x43mm round. There were also limited tests carried out with 50 grain bullets.To increase penetration the cartridge-case was changed to 4.85x49mm. some were coded with a purple tip (=experimental). None of the 4.85x44mm had a headstamp. The 4.85x49mm were headstamped RG 76 4.85 and RG 77 4.85. (RG=Royal Ordnance Radway Green)


5mm with CNCS envelope  (Collection Mr. Edwards)

5mm with GMCS envelope, (4.85x49mm for comparison)


To develope a good tracer round, ten different experimental designs were produced. Finally the "K-type" was selected to participate in the NATO trial (as tracer XL2E1). The round is marked with a red bullet tip and gives a red trace. (with dark ignition)


At least two versions of proof rounds were produced. The first version can be identified by a red painted head and groove. The second version is copperwashed, (the usual way in the UK to mark a proof round). The copperwashed cartridge was produced in very limited quantaties (for illustration purposes) only. 

Short range:

The short range round used the same case as the ball and tracer round. The bullet was roundnosed, made of plastic. (in white and black plastic) 


There are four different versions of drill rounds produced: 

  1. - A 44mm case with a 5mm collar to make it a 49mm case,  without a cap.

  2. - A cartridge with three holes drilled in the case, the bullet  and neck are stained black.

  3. - An empty service round without a cap.headstamped RG 76 4.85.

  4. - A chromeplated case with three red painted vertical flutes. 

Inspectors dummy:

For illustration purpose only, a very few inspector dummy rounds were produced. A chromeplated case with no flutes. The cartridge was used by technicians in the fire arms factory.

Metalic blank:

  There are two groups of blank rounds produced. 

  1. - Messing blanks, 

  2. - Blanks made of metal and plastics (discussed later).

It was very difficult to draw extended blanks, the walls were to thin and to weak. So they quickly dropped this concept and stepped over to a combination of metal (messing / aluminium) and plastic. At least two versions of metallic blanks were made:

  1. - A extended case, closed with a rosecrimp.

  2. - A standard case, closed with a rosecrimp, the tip painted green.

Plastic/metal blank:

Several blanks were produced, made from sawn of cases and plastic bullet shaped front pieces (hollow). White, black and transparent plastics were used. A version with a light alloy head and the rest of the blank made of plastic was also tried.

Plastic training:

The plastic training round was also made from a sawn of case and a plastic bullet shaped front piece. When fired the solid bullet was torn off.

Collection Mr. Edwards.


To be able to fire a rifle grenade from the 4.85mm Individual Weapon a grenade cartridge was developed. Astandard case was used, closed with a rosecrimp. See image.

Collection Mr. Edwards

Armour Piercing:

There were also some tests conducted to produce AP rounds, using a hardened steel core (sometimes in combination with a lead/antimony base) in different sizes, with different weights. these bullets were marked with black rings painted just below the bullettip.

Two of those AP rounds are showed in a factory made presentation box (together with a 4.85x44mm ball, a 4.85x49mm ball and tracer round, all sectioned)



from left to right: ball, exp ball, tracer, drill with collar, proof, blank, short range