Sorry to disappoint you, but... no, your find is note a nose-cast Minie bullet. What you see on it is the impression of the ramrod's mouth. Usually the ramrod does not make an impression on the bullet during ramming. But when the gunbarrel has become "fouled" with powder-ash from repeated firing without cleaning, the fouling can make it very difficult to push the bullet down into the bore. When that happened, during a daylong battle, civil war soldiers' diaries mention having to pound on the ramrod's end with a rock to get the bullet loaded down the barrel.
Your bullet definitely has been rammed and fired... the base-view photo shows its base rim expanded outward into gunbarrel with three wide rifling-grooves (most likely a yankee Springfield).
A nose-cast bullet almost always shows either a flat tip (like you see on a Williams Cleaner), OR flat where the casting-sprue was cut off (like in the photo below), OR a projecting casting-sprue (like in the other photo below). All Gardner minies were nose-cast. You can see the uncut casting-sprue on the photo below showing "unfinished" Gardner bullets, as they looked when they came out of the mold.