Interesting reduced (gallery, short range) round from Hungary which center fire. The manufacturer is Vadásztöltény- Gyutacs- és Fémárugyár Részvénytársaság, Budapest.
we had already discussed this 2 times…
Here the second thread: 4.5mm auxillary cartidge
It shows boxes and instruction leaflet, for which gun a.s.o. (its from about 1948)
Thank you. I searched for 4.5x9 R.