Modify the Receive by Item screen so that when an item has an Average Weight and does not have a Constant Weight, it will populate the Weight Received field with Quantity Received * the Average Weight stored in Inventory File Maintenance.  

 

This calculated weight value could be changed.  Should it be decided that the Quantity Received needs to be changed; the Weight Received will only be recalculated if Weight Received is set to 0 first.