Well...you don't need a full choke to get a full choke pattern with steel shot. You can use an improved cylinder or modified choke with steel shot and get as tight of a pattern as a full choke with lead. So I wouldn't say the fact that you can't use a full choke is a reason to not use steel shot for turkeys. Lead shot does have an advantage at longer ranges because it doesn't lose its velocity as quickly as the lighter steel shot does.