Great find. I believe it could have well been the head to a war club, perhaps passed down for generations. I make that speculation because I have seen many authentic Indian clubs of of the post-contact timeframe, and even the wooden ball clubs sometimes featured a 1/2-1" protrusion, because that was a very quick killing design, since a hole was literally punched through an enemy's skull by the club, as if hit by a hammer. Bashing was not enough in warfare where brute strength was the basis. Of course you know the popularity of the tomahawk as a steel tool with Indian design requirements, with the hammer or pipe poll opposite the blade.