that should be a cz52 chec surplus army pistol in 762x25, nice old pistols that shoot pretty good, horrible trigger, C&R eligible , has the roller locking recoil system it will throw brass into another zip code. you can reload quiet a bit over the 30 cal. mauser specs. slide should be stamped with date of 52-53-54 one of the numbers will be the year of production they were only made in those years. feel free to pm for any advice you need on it.