Rolling Thunder (movie, 1977)

A Vietnam veteran, Charles Rane, returns home after years in a POW camp and is treated as a hero. When thugs invade his home to steal the silver coins he received for his service, they mangle his hand and leave him and his family for dead. Rane survives and becomes obsessed with getting revenge. Aided by his loyal friend Johnny Vohden, Rane, now wielding a hook for a hand, sets out on his mission of vengeance.