Definitely a “covert contract” of .303 ammo for Egypt.
The “AOC” is a Caeser Cypher ( yes, Julius Caeser) made by shifting the l;etters one space in the alphabet. Hence “AOC == BPD”.
1340 looks like an “Islamic” date, , purported to be “1922” in the Gregorian calendar…only one problem in that, is that 584 ( Assumed date of Manhood of the Prophet, not his Birthday, which was CE 570.) is the commonly used ( Turkish) method of Islamic dating on ordnance…Most Islamic countries have also used 621.6 as a reference point ( AH Anno Hegira, the date of the escape to Medina) as the common everyday translation of Religious Dates.
Add to that the nature of the Islamic Year ( 364 days) against the Gregorian Year ( 365.26 days, and you can get an accumulated error, which the Julian ( Caeser again) and Gregorian calenders reduced by introducing the Leap Year.
As to whether the date of 1922 has the significance of Egyptian “nomal” independance ( from British suzereignety to the “Kingdom of Egypt” ( under the Farouk family) but still with a “British Resident” effectively controlling Egypt’s foreign Policy and defence; and the new found Nasser Independence of the Arabic Republic of Egypt…is a Hisdtorico-Political question…
Now the “chemical cleaning” of the cartridges…year ago I acquired hundreds of Surplus 7,9mm ammo, BPD 953, with a similar chemical wash colour…also purported to be Egyptian Surplus…48 round Boxes, etc.
The headstamp style (Bunters) and manufacturing “signature” was Identical to the .303 “AOC” cartridges.
Whether the wash was applied by the Israelis in the late 50s, or it was some other Importer’s doing, I can’t say.
What is obvious is that Italian made .303 Ammo ( it was also still in use by the Italian armed Forces in the 1950s and 60s) was based on the 1920s design of Mark VII (z) ammo ( CN plated bullet, large diameter primer), and this design was done by all Italian makers of the cartridge ( primarily for Regia Aeronautica before and during WW II, all forces after 1945). I have a Fiocchi catalogue offering .303 FMJ in the 1950s, and also the primer cups… .250" size ( ie, identical to British primer). The Italian Army and Navy had large qty. of SMLE and No4 rifles right up to the 1990s (used dropped off after late 1960s, for training mostly)