At the end of 1954, Soviet weapons began to be available in large numbers in the USA for testing thanks to various spy and subversion operations. Unfortunately the weapons arrived with little or no ammo.
The amount of ammo needed for the Aberdeen Proving Ground was far beyond what was available. A contract was awarded in 1955 to the HP White Laboratory to produce a set of 500 7.62×39 M1943 rounds for the assessment of the recently made AK47 rifle. To speed delivery, the lab decided to turn cases of .220 Swift into M43. This ammo was then marked “SUPER SPEED 220 SWIFT.”
In July 1970 lake city produced the ammo to support US special forces operations.
The ammo was packed in small grey-brown boxes of 20 rounds and then packed in 1000 round wooden crates. The markings was limited to “20 cartridges AK47 rifle ammo 7.62x39mm” followed by the lot number.”
http://looserounds.com/2020/02/17/us-lake-city-produced-7-62x39/
The amount of ammo needed for the Aberdeen Proving Ground was far beyond what was available. A contract was awarded in 1955 to the HP White Laboratory to produce a set of 500 7.62×39 M1943 rounds for the assessment of the recently made AK47 rifle. To speed delivery, the lab decided to turn cases of .220 Swift into M43. This ammo was then marked “SUPER SPEED 220 SWIFT.”
In July 1970 lake city produced the ammo to support US special forces operations.
The ammo was packed in small grey-brown boxes of 20 rounds and then packed in 1000 round wooden crates. The markings was limited to “20 cartridges AK47 rifle ammo 7.62x39mm” followed by the lot number.”
http://looserounds.com/2020/02/17/us-lake-city-produced-7-62x39/