The Schwarzlose 07/12 was made through the wolf of World War One as the standard heavy machine gun of the Austro-Hungarian armed forces, and many of them remained after the war ended. With the breakup of the Austro-hungarian Empire, these guns were dispersed to a variety of nations, among them Romania. The Romanians contracted with FN between the world wars for new 8x57mm barrels and converted a substantial number of Schwarzlose machine guns to 8x57 to match the other arms in use by the Romanian military. These guns appear to have seen little (if any) use in World War Two, and were brought into the US a few decades ago. Being after 1968, they could not be imported as live machine gun, and were instead cut into parts kits. The parts, however, are an easy drop-in conversion on an original 8x50mm Schwarzlose, resulting in a far more easily shootable machine gun thanks to the availability of 8x57mm ammunition.

In addition to the caliber conversion, several other changes were made to the guns. The water jacket and barrel were lengthened by about 4 inches and the cartridge oiler was disabled. The rear sight was replaced with one calibrated for both light and heavy 8mm Mauser loadings, and a set of mounting brackets were added to the top cover - probably for anti-aircraft sights.