We have five different unheadstamped Argentine made variations in our reference collection. I don’t have them at hand to take pictures, but I do have a description of each one of them:
1 - Ball: tinned brass jacket.
2 - Ball: tinned brass jacket held by three stab crimps.
3 - Proof: brass jacket with two indentations on the side and held by three stab crimps, red primer sealant.
4 - Proof: tinned brass jacket with two indentations on the side and held by three stab crimps, red primer sealant.
5 - Proof: tinned brass jacket with two indentations on the side, red primer sealant.
All of them have a flat brass primer with beveled circumference.
Regarding the manufacturer, we can assume that these cartridges were made by FM “San Lorenzo” during or after 1958, because they look very similar to cartridges headstamped F.M. “S L” - 58 - 7.65, which also exist as proof loads with or without red primer sealant. However, we must keep in mind that this cartridge was offered in FM “FLB” catalogs until c. 1978 -not longer listed in c. 1982 editions-, which means they could be of much later manufacture. These late catalogs even show the picture of an “all red bullet” variation of this cartridge, like those made in 6.35 and 7.65 mm Browning, but as far as I know no specimens are reported to exist. Also, it’s worth mentioning that there is a full auto variant of the Hi-Power pistol chambered for this cartridge that was reportedly made in 1974, so it is quite possible that fresh ammunition was used to test it.
The unheadstamped round taken from an Eley box has a CN jacket and oval brass primer (no bullet crimps), and the unknown has a CN jacket held by three stab crimps and a flat copper primer.
The “MANNLICHER 7,65 D” was made by Gustav Genschow before they adopted the Geco headstamp.