Thanks for the tip. I posted a similar method here in October. It used DataTable.CreateDataReader()  to return an IDataReader
 public static class IListExtensions
    {
 
        public static IDataReader ToDatataReader<T>(this IList<T> dataList)
        {
            var dataTable = new DataTable();
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
 
            foreach (PropertyDescriptor property in properties)
            {
                var type = Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType;
                dataTable.Columns.Add(property.Name, type);
            }
            var propertyValues = new object[properties.Count];
            foreach (T item in dataList)
            {
                for (int i = 0; i < propertyValues.Length; i++)
                {
                    propertyValues[i] = properties[i].GetValue(item);
                }
                dataTable.Rows.Add(propertyValues);
            }
            return dataTable.CreateDataReader();
        }
    }