The information provided by the gunslinger TV series did not mention that the series had 40 episodes, nor did it mention that it could be watched for free. Therefore, I don't know if the gunslinger TV series has 40 episodes and if it's free to watch.
" The Gunslinger " was a Chinese the mainland of China directed by Zhao Qing and starred by Luo Jin, Miao Pu, Yu Zhen, etc. It had a total of 36 episodes. The plot revolved around the sharpshooter, Tang Yujin, who had won the shooting championship. He was a general practitioner who had returned from Germany. He opened a clinic in Shanghai and treated patients while secretly searching for the murderer who had assassinated his father. The story took place on the eve of the Battle of Songhu, where all walks of life in Shanghai united to fight against the Japanese. Tang Yujin had originally stayed out of it, but after experiencing the pain of his fiancée and his family dying under the Japanese gun, he resolutely joined the New Fourth Army and joined the annihilation of the Japanese invaders, becoming a hero of resistance on the battlefield in northern Jiangsu. The drama was first broadcasted on Jiangsu variety channel on December 23, 2014, and was released on Tianjin TV's Happy Theater on December 5, 2015.
'Gunslinger' was a Chinese drama that starred Luo Jin, Miao Miao, Zhan Jingyi, Yu Zhen, Sun Wei, Chen Jie, and other actors. The plot was about the sharpshooter Tang Yujin, who had won the shooting championship. He was a general practitioner who had returned from Germany. He opened a clinic in Shanghai and treated patients while secretly searching for the murderer who had assassinated his father. The series revolved around his principle of not using guns to hurt people, and also depicted the story of Shanghai's people uniting to fight against the Japanese on the eve of the Battle of Songhu. You can watch the complete series of the Gunslinger in high definition online videos on Mango TV, iQiyi, and other platforms.