I would do as well. When I first read your post, I thought I read 6.3x62 - LOL. When you stated what several people had said, I thought WTF? Went back and saw my error.
Depending on the 9.3x74 ammo, could lose some case material into your chamber and bore as well. Much would depend on the ammo used. I have seen brass that became brittle, to lose chunks when fired.