I don't believe the bullet has been carved, I think it's been pinched in a clamp of some sore, perhaps a vice, and the brass removed from the bullet, for what ever reason; perhaps to save the powder, or just to render the bullet inert. The reason I say this is because I've done it when I was younger, before I had a bullet puller and reloading equipment, and your bullet looks just like the ones I've clamped in a vise.