I recently stumbled across a site hosting the annual command histories for the Commander in Chief Pacific (CINCPAC) from 1960 through the mid-'80s. I found an interesting tidbit in the 1970 history regarding US production of 7.62x39mm ammunition for the Cambodian Army.
[quote=“Commander in Chief Pacific Command History 1970 - Volume II, pp 259-260”]Assistance for the Cambodian Army
[u]AK-47 Rifles/Ammunition[/u] (TS) The U.S. and RVN began supplying FANK with captured AK-47 rifles and ammunition in April; however, an additional source was needed to meet FANK requirements. [b](Redacted text)[/b] The remaining 1,420 AK-47 rifles were scheduled for delivery on 17 January 1971.[i]2[/i] (TS) On 31 December, Cambodia MAP was supporting a density of 68,973 weapons that fire AK-47 ammunition. After delivery of the remaining Indonesian AK-47s, the density will be 70,393 weapons. The 30-day ammunition consumption rate will be 8.73 million rounds. To provide a guaranteed continuing source of supply to meet the Cambodian MAP requirement for AK-47 ammunition, production is underway in the Continental United States (CONUS) under a contract paid out of Cambodia MAP funds. CONUS production was 20 million rounds for the period October through December. On 8 January 1971, the SECDEF approved CINCPAC's request to increase CONUS production to 9.5 million rounds per month. The first two million rounds of CONUS production AK-47 ammunition was airlifted to the RVN on 20 November. The first surface delivery arrived on 1 December with 5.96 million rounds delivered by 31 December. An additional 9.180 million rounds was scheduled to arrive by 13 February 1971.[i]1[/i]
(Redacted text) He stated that costs being equal, insertion of M-16s into Cambodia as the standard infantry weapon was much preferred to building a weapon system (AK-47) which was not U.S. supportable without parts engineering or tenuous third country support. However, additional AK-47 could be utilized provided they were procured at no cost to MAP and with no strings attached.2
2. J4312 Point Paper, HQ CINCPAC, 28 Oct 70 and 8 Jan 1971, Subj: AK-47 Rifles/Ammo for Cambodian MAP.