I found this three ringer

[Truth]

I found this three ring or at a Oldfort from the early 1700s through 1930. It’s nothing like all the other three ringers I have found they’re Less pointy any help would be appreciated

 

[fyrffytr1]

I think your calipers are off on the digital readout. If the first picture is diameter, according to the scale readout it should be about 13.4mm and the length should be about 25mm. That converts to about a .54 caliber that is .98 inches long. Does this sound about right? If so it is just a variant of a U.S. manufactured .54 3 ringer.

 

[vpnavy]

I pulled this from another TN thread...

Civil War Bullet ID Chart (Sep 05, 2013)

Civil War Bullets (Sep 26, 2019)

 

[smokeythecat]

I also agree that's a Union minie. Always nice to see one come out of the ground.