Even if you don't put the ActionForm in session scope, you can still use the same ActionForm for multiple actions. All you have to do is specify the same name attribute. For an action, it's not the name that must be unique, but the path. Here's an example:
If you don't put the ActionForm bean in session scope, then Struts will create a new instance with each request, so if you want to share data between actionOne, actionTwo, and actionThree, then azhar is right... You would have to put the bean in session scope.