Found over weekend. Wasn’t sure if this was related to a mini ball.
I need to get more books for sure. There’s a lot to consider in identification I can tell from your post. I appreciate the in depth response.The presence of pure-white patina suggests the bullet is made of pure lead, not a "hardened-lead alloy," such as Burnside and postwar repeating rifle bullets used. So I believe it is from the civil war, not a later vintage.
The only civil war bullet I've seen that has a "3" on the bottom is an Enfield. This bullet clearly isn't one of those.
I cannot see the "3" in your photos. We need a well-focused closeup photo showing the "3" marking. Also, is it a raised number or indented number?
Your bullet's flat solid base indicates it was made for use in a Breechloader. Comparing its (damaged) diameter with its length suggests it is a .50 to .58 caliber. I suspect a Sharps or a Starr, due to the apparent lack of "deep" body-grooves, like we see on a Spencer or Merrill. But its nose is too rounded to be a typical yankee Sharps. So if I had to hazard a guess, I'd say it is a fired Richmond Arsenal Sharps, or a fired Starr Carbine bullet. See the photos below.
Rifling-marks are clearly visible on at least half of the bullet's sides. Careful study of the number of grooves on that half, multiplied by two, COULD tell us the number of rifling-grooves in the gunbarrel which fired your bullet. Your photo showing the grooves on one of the bullet's sides is not well-focused enough for me to count them. So I need to ask you to please try to count them. Remember to multiply by two. A magnifying glass might help.
Lastly... firing impact has clearly changed your bullet's shape --- but that did not change its weight. Please weigh your bullet on a super-precise scale, and tell us the weight-measurement in Grains. (A jewelry shop might way it in Grains for you.)
The super-precise weight of various civil war bullets (in Grains) has been recorded in several books on civil war bullets. It might be helpful to simply search those books for your bullet's precise weight.
Please let us know what results you get from the various tests I've suggested.
I forgot to mention:I need to get more books for sure. There’s a lot to consider in identification I can tell from your post. I appreciate the in depth response.