Don't know about the carbines, but I do have a Bulgarian long rifle here, 1903 on a Model 1895 action, Bulgarian receiver crest and all. It has been converted to 8x56R30M, which Bulgaria adopted shortly after Austria and Hungary adopted the same round.
Before the Great War, there were just the two big arms-exporting factories on the European continent: DWM and Steyr. DWM was made up of the small rifle-and-design plant of the Mauser brothers at Oberndorf a/N, the German Metal Cartridge Works at Karlsruhe and the Ludwig Loewe rifle plant in Berlin. Loewe manufactured rifles, lots and lots of them and the DM plant made ammo; Mauser made some and did the rifle design. Also employed at DWM's Berlin plant were Georg Luger (and we all know what he designed) and Karl Heinemann, who was really into machine-guns. That seems to have been enough for Germany. In Austria, you had the Ritter Ferdinand von Mannlicher and Sylvestr Krnka designing for the Austrian Weapons Making Company at Steyr and George Roth making ammunition in his own plant. With the few remaining national arsenals, that took care of Central Europe.
Most of Europe did not have modern gun-making factories, but relied on the two giants.
In Belgium, FN had been started, but the FN was started speciaifcally to make the Mauser Model of 1889. They did not have the equipment..... or a licence..... to make the later Mauser rifles, only received the machinery as war reparations in 1919/20.
In England, you had BSA as the SOLE big commercial rifle-maker and Vickers, Sons and Maxim supplying machine-guns, Pom-poms, automatic cannon and semi--automatic single-shot ships' guns to whoever wanted them.
Much the same situation pertained in artillery: Britain had Armstrongs', Germany had Krupps' and the Austrian Empire had Skoda. There WAS nobody else in Europe. Czechoslovakia became an arms giant between the wars, but they did so on seized German and Austrian equipment, same as Poland and a bunch of others.
If you didn't have the technology to mass-produce your own weapons, you went to the people who DID have it. If your people came up with a good design, one of the big guys might even make it for you: Mauser-Vergueiro is like that. Or you could design your own cartridge and they would make it for you: 6.5x54 Mannlicher-Schoenauer.
In the Balkans, Romania didn't have production capability, so Steyr made their Mannlichers for them. Bulgaria, right next door, also wanted more rifles..... so they bought from the closest supplier: Austria. But they were BULGARIAN rifles: you could tell from the Royal crest on the receiver.
The day of CAD, CAM and CNC machine-tools still was almost a century away.
And the big Continental plants could give REALLY decent prices, too, as every rifle they built had a built-in subsidy for the factory, which enabled them to train and keep a larger work-force than was necessary in peace-time. And this was exactly what was needed in the first week of August, 1914.
The rest, as they say, is history.
Eight and one half million servicemen and five million civilians died in the Great War.... and still it shapes our lives today.
Sorry to preach, but that's why.
You can try mine out when you are through this way; I'll have ammo by then.
