Are there trains to travel from Changsha to Hong Kong end of October 2017?

There is no through train from Changsha to Hongkong. But you can have a transfer in Guangzhou or Shenzhen. The G rides are available from Changsha to Guangzhou and Shenzhen. The transit is convenient. The rail service is also available from Guangzhou east station to Hongkong Hung Hom station.