Do you guys think Hackberry or red elm could make a nice recurve bow? how wide should the limbs be near the handle and at recurves in your opinions?

Never made a bow from red elm, but have used hackberry a couple of times.  I had decent luck with it.  For hackberry I started at 1 7/8" at the fades and tapered in a straight line to 1/2" tips.  If you want to recurve the tips, leave them a touch wider to begin with.  You can always narrow them up later if the recurve is holding well without pulling out or twisting.  However, I'm not all that good or experienced with white woods, so another's opinion will be more beneficial here.

Well thanks for your help.