I have had some good luck with persimmon, it frets really easy, like B-locust or B-walnut, but otherwise makes a good bow. Too high a crown will crack on the back. not really great in tension or compression in my personal opinion, but it sounds like your trees are wide enough you wont have to worry about crown issues... most of what I get down here are saplings. It does tend to twist really bad during and after splitting. It's really gamble with persimmon, some twist like crazy, some stay straight. don't chase a ring, just peel the bark and seal the back and ends with wax. You'll definitely want to re-seal the back b\c it will check bad otherwise. You can't leave the bark on either b\c the borers love the stuff.. Wouldn't hurt to spray it with a little insecticide anyways, but if you leave the bark on, they will just eat them to pieces.
the trees that I have down here will turn black on the back if you gently remove the summertime bark and seal with hot parrafin wax. It takes a week or so to turn black.... but pretty much all of them do it that I have cut. The belly takes on some green colors, but if you knick the back, the black will chip off...its only paper thin so if you like the black, don't sand it, just heat gently and wipe the wax away.