For you Iron-heads, it sure looks like a Hotchkiss, but it's lead and .52 caliber!
This is a three-piece bullet; a hollow nose section containing at least a percussion cap (perhaps more), a middle band, and a base cup with rusty remnants of a central iron pin.
0.525" x 1.11" overall. From the same collection mentioned in other posts...will have it at Franklin.
