If I am seeing correctly that's a pretty tiny caliber and a lead exposed nose. No more than .223" or .224" by the looks. And that is a good candidate given the cannelure.
I'd guess a 52 to 55 gr. soft point from an old style .223 Rem/5.56mm NATO . . . or a .222 Rem or .222 Rem Magnum, etc., etc..