3 ring bullet

[stlfiction]

i found this today at a local park with my little brother (its my first three ringer ever) i was wondering if someone could tell me the era it would be from< i would think it would be old cause i found it in a park, but its got a perfectly flat top and its not from impact so if anyone could tell me that would be great. thanks

 

[tencents]

What's the diameter? It appears to be a modern bullet called a wadcutter used for practice.