Not sure if I have a civil war slug

[caselhall]

Found near a civil war battlefield, now hunting ground. So I'm not sure if it's modern or civil war era?

 

Amazon Forum Fav 👍

A History of Mining on the Kenai Peninsula, Alaska - Grab it through Amazon!

[Montana Jim]

Even if you can compare it to known calibers, you're likely to never know when that lead was used, fired or dropped. That would be an impossible attribution in my opinion.