Yep. Looks like your typical cut "square" nail. Don't know why, but those always seem to be in better shape than the wire nails. http://www.uvm.edu/histpres/203/nails.html
There is a site I metal detect that has accidentally produced some flakes and a scraper. Hoping to stumble across a point sometime.
How do you go about digging for arrowheads? Just dig and sift?