Does it make a difference whether I let my staves dry horizontal or vertical?
Thanks,
Brent

no

I hope not, I been keeping mine leaning against the wall for the last 18 years.
 Full staves, no. If they are reduced to near bow size then I would lay them horizontal, belly side down.

That's what I wanted to hear and from two of the best.
Thanks,
Brent

No,But there is a way to put a little reflex in them.If you don't like to use heat.
 Cut staves long if you can.I cut mine 80" long.Put the ends up on the 2 saw horses.Tie a cinder block in the middle off the ground.Let season.They must be stored out of the sun.
  Now your staves will have a little natural reflex.Your staves won't look like U's but will pick up a little reflex without useing heat.
   The more natural your staves the more durble your bows will be.Meaning the longer they'll last.