I have two five round magazines and I have no idea what they go too. Both smoothly chamber 7.62x54R which makes no sense to me. I have not been able to find anything that fires that round and uses a similar magazine. One has markings: Santa Fe Magazine Made in Japan Upon doing some research I notice the British Enfield .303 uses a similar style magazine but it appears they were only made in 10 round magazines. The other is brass, shorter and boxier with no identifying marks. I don't know why I have become obsessed with this but I really want to track down the firearms the work with. I might want to purchase them.