Ha! yes, of course. In my life I used some of these, but they are dated. CCCP means 'USSR', there is no such a country on the map since 1991.

Oh btw - 3 copecks isnt silver. It is not even a decent copper. It's just some kind of copper-zinc alloy.

ps. all of the finds in your soil are extremely cool, but these two I liked most:

a copper Penny from 1917 and a 1920 silver thruppence, which were called Tickeys here.

the older - the better!