The fact that some of these Maxi-Ball bullets have been "found at Ft. Oglethorpe GA" does not mean they date back to the Spanish-American War (1898). For example, I dug a pocketfull of very-modernday FIRED .58 Lyman Mold blackpowder repro Minie bullets in a patch of deep forest at the Cold Harbor VA battlefield. (Not on the National Park land there, of course.) Maxi-Ball blackpowder bullets are from no earlier than the 2nd half of the 20th-Century. For proof, see the photos below. Note that Charlie P. (NY) gave the exactly correct ID-name for them, a Thompson Center Maxiball.