The Cherokee, darts, were made of hickory, and other woods, and were anywhere from 12-14 inches or so. There is historical reports of the Cherokees taking game as large as Racoons. With a heavier dart, you could use a broad head, small, but sharp. I have flattened out the little steel darts, for the commercial blow guns, and they penetrate quite well. They are not super wide, and are very sharp, and are mainly leaf shaped. I don't know if the Cherokees, used any form of broad head, but again, there is historical records, of them shooting squirrels, in the eye, and killing rabbits out from quite a distance, I believe it was like 50 yds. or so, or maybe even more. But the first Europeans were quite impressed by the skill of the Indians, and their blow guns, and darts.
Wayne