Tony - I have an original English-Language copy of the Greek Powder & Cartridge Co. Ltd. Company History/Catalog covering the period 1874-1939. On page 183, It shows the “Light Machine-Gun” (no other designation given) and has specifications on the cartridge, but does not show the cartridge.
Following is a reproduction of the table of specifications:
Continuous or Intermittent firing at will (I assume this means “full or semi-auto fire”)
Rate of fire (theoretical)…720 round per min.
Practical Range…750 m.
Weight of light Machine-gun (empty)…4.150 Kgs.
Length over all…900 mm
Length of Barrel…400 mm
Length of cartridge…53 mm
Length of cartridge case…36 mm
Length of bullet…22 mm
Weight of bullet… 8 gm.
Weight of charge…1.2 gms.
This must have been a 1939 development, because it makes the following comments about the gun:
"The light Machine-gun shown below enters into our Manufacturing program and has been entirely designed in our Factories by our technical services.
"Some of these light Machine-guns have already been manufactured in our small arms Plant."
The use of capitol letters, spelling, etc. are as in the book.
The only rifle calibers shown, with pictures, in the catalog section are the following:
6.5 mm Mannlicher Schönauer (Shown exactly as that in the table)
7 x 57 mm Mauser
8 mm Mannlicher (case length not shown)
7.92 mm Mauser
7.65 mm Mauser
7.92 Hotchkiss (I assume this is a machine gun loading of the 7.92 Mauser, but not sure of that)
7.85 mm Lebel (designation from the table. The picture shows the cartridge as “8 mm.”)
7.7 mm British S.M.L.E. (.303 British)
Above data on pages 142, 143. They also manufactured the 13.2 mm Anti-Aircraft cartridge, as well as better rounds, shotgun shells, and a wide selection of pistol and revolver cartridges.
I am sure that Chris Punnett knows that the .450 Revolver is listed here. I hope for his sake it is not as rare as the 9 mm Bayard, also made by them. I have not found a specimen to acquire in 45 years of collecting auto pistol. There is one in the Woodin Laboratory, but with a very poor headstamp stamping.
On page 148, the mention the types of “Special Ammunition” they made:
For Anti-aircraft and Anti-tank defence:
The wording of the text would indicate that these loadings are found with the caliber spread of “6 mm” up to “8 mm” for rifles and LMGs, and from "12.7 and 23 up to 13.2 mm for HMGs.
The text on page 149 indicates that the “Aim-correcting cartridge” must be similar to the German B-patrone.
Hope this is of some help and interest.