For your consideration one, slight length variant, of a Thomas RBRF4 bullet 288 Vicksburg rifle bullet. A very interesting bullet that's in excellent dug condition. The patina is...just what you see in the photos...a real nice patina! This bullet has a very well defined nose cast mark. Both mold seams can be faintly seen & the cavity is a cone. Measures about 0.515 x 1.145 inches.
A Vicksburg rifle is a Kentucky or country rifles rerifled to .54 cal.