Civil War Bullet?

[cmthunder]

Found this at a Union Civil War camp in Maryland. Can anyone help with id?
D-.379
L-.672
Grains-185
Thanks

 

[CreekSide]

I’m not positive but I believe that the base would be indented if it was CW but I’m sure others will know

 

[cmthunder]

I’m not positive but I believe that the base would be indented if it was CW but I’m sure others will know

No there are plenty of flat base bullets!
Minie balls have cone etc

 

[CreekSide]

No there are plenty of flat base bullets!
Minie balls have cone etc

I see the rings on it. I’m not a bullet expert but maybe someone will see this and respond

 

[fyrffytr1]

I have looked through several reference books without luck. I get the feeling it is post civil war and probably from the 20th century.