357, I just bought a High Standard Victor made at East Hartford this week. I too was looking for a spare magazine. I found two originals at a local gunshop. The gunshop owner told me any High Standard magazine would work from a Trophy, Victor, 106 , 107, or the later Military models. I guess these guns are somewhat fussy about feeding from the magazine properly. When you get one to work perfectly ( I'm talking one mis-feed in several hundred) mark it some way and don't drop it. I was also told to stay away from after cheap market varieties if you don't find an original. Brownells have some good replacements for around $30. I hope this helps. Good luck!