I'm guessin you're referring to hophornbeam as ironwood. I read an article by Marc St Louis in a magazine last month and he said something that I thought was very interesting.
He said, "Hophornbeam is a very elastic wood and will, in many cases, make a better bow than Osage. The only disadvantage, when compared to osage, is that it will not tolerate high moisture as well." Marc St. Louis
I've never worked with hophornbeam myself, but having worked with lots of osage, that is making a pretty big statement.