Bullet id, found today, Gardiner explosive?

[oddballaffliction]

Hi all! Did some digging the last couple days (2 different sites in as many days!) Found this in a supposed Confederate camp site, and thought it rang a little higher than normal, but figured it was ground conditions. Got it home and cleaned, and am I correct in thinking this is a Gardner explosive bullet?! Looks more of the sort of pewter material that the one in my collection is made of. Found it right near a fired ringtail sharps and a pistol ball. My usual luck says it's not... Thanks!