Yes, it does shoot exactly the same cartridge ! In fact, that famous and long-lived rifle cartridge (named Gewehrpatrone 11 or GP 11) was used in the Army from 1911 until, let's say, around year 2000 for Reserve soldiers still equipped with the Stg 57 at that time. However, it is still widely available here, even in original military boxes. The K31 (Mousqueton 31 in French) is a much-loved and popular rifle here in Switzerland. I paid about $ 100 for mine (coming from Army surplus). My fave Swiss military rifle is the "Mousqueton 11" or K11, also available in a longer version, the "Fusil 11". It was progressively replaced by the K31 before and during WW2. I joined a picture of the mousqueton 11. The latest rifle I had while still on active duty was all-plastic, lighter than the Stg 57, but it needed to be cleaned very often because of the gas system and would sometimes break if thrown onto a truck while boarding it in emergency (didn't you have the same problem when the M-16 was put into service
?) ! To me, it was more an expensive toy than a real assault rifle. We also found out that our federal authorities wished to get closer to NATO because of the caliber... despite what they said.