So, I forgot about the Hotchkiss 25mm/60cs made in Spain. Simile to
http://www.navweaps.com/Weapons/WNFR_25mm-60_Hotchkiss.php These machine guns were supposedly built in Spain and made wholly or partially with Vickers' involvement for the Mexican G20 and Durango classes which were being also built in Spain.
Perhaps the Argentine intention of the 25mm/70cs for their destroyers was born from this experience.
How on earth did they manage to add 1300kg in total weight?
Protection?
Do you have more data on this 25mm vickers gun? Design date, mv shell weight etc? Was it an Oerlikon competitor?
You can access here (spanish):
https://fdra.blogspot.com/2016/05/ara-canon-aa-de-254mm-vickers.html. Being the original source: (english)
www.quarryhs.co.uk/Vickers25.4.htm.
Drachinifel made a video about La Argentina and stated in the comments that the original idea wasn't for it to have 25mm/70cs machine guns but 40mm/39cs. I find this strange, because Argentina didn't use those machine guns of purely British origin but rather of Italian origin (Vickers-Terni or Odero-Terni). I wouldn't be surprised to find in future documents that Drachinifel was partly right and that the machine guns initially considered were none other than the 40mm/50cs mentioned in this topic.
At the time the cruiser La Argentina was (at a lengthy pace) being built (1935-1939), Argentina negotiated the purchase of these machine guns:
- 20mm/65cs (single) Rheinmetall-Borsig, exclusively and in service for the Navy.
- 20mm/70cs (single) Oerlikon, exclusively and in service for the Army*.
- 25mm/70cs (twin) Vickers-Armstrong, exclusively and in service for the Navy.
- 37mm/57cs (single) Rheinmetall-Borsig, exclusively and in service for the Navy.
- 40mm/50cs (single) Vickers-Armstrong, offered but never in service to both Army and Navy.
- 40mm/56cs (single) Bofors, for both the Army and the Navy; in service in the Army but not in the Navy*.
By this I mean that the Oerlikon 20mm/70cs machine guns were not a priority for the Argentine Navy. And no documents appear to have survived that compare the Vickers-Armstrong, Oerlikon, and Rheinmetall-Borsig machine guns (of similar caliber).
*Used by the Navy since postwar.
Most likely, the drawings were transferred for calculations during the preparation of design documentation for the 3rd series destroyers (new Cervantes).
Yep
And it wasn't just Great Britain. Almost all production of anti-aircraft artillery was concentrated in countries at war or occupied (France - Hotchkiss and Denmark - Madsen).
Sweden (Bofors) was the exception, but even they were limited in arms supplies at that time, even to non-belligerent countries.
Of the machine guns I mentioned earlier, the Argentine Navy's Bofors 40mm/56cs were completely requisitioned and used by Sweden. The same is true for the Rheinmetall-Borsig 20mm/65cs and 37mm/57cs machine guns, which were partially requisitioned and used by Germany.