Cry for Me, Billy

Cry for Me, Billy is a 1972 American film directed by William A. Graham. It stars Cliff Potts and Maria Potts.
It was also known as Count Your Bullets and was one of the first films from Brut Productions.
Plot.
Hardened gunslinger Billy is tired of violence and bloodshed. After encountering a group of Apache prisoners under the care of a racist US Army sergeant and his men and giving them some water, Billy speaks with a friend about a possible job position far from there. When he's out he discovers that all the Indians were murdered save for one girl taken as sex slave for the soldiers.
Billy follows the soldiers in search for the girl that he wants to save, finding that she escape on her own. After earning her trust, both Billy and the Indian girl named Flower travel together. They come across a cabin where Billy avoids an ambush by the owner and his son, keeping them both at hand with his shotgun. Decided to take some goods from the cabin, the owners offer to sell what he want for money or in exchange of sex with Flower, which he reacts angrily, forcing them to run. 
Billy and Flower keep their march together in the wilderness using only Billy's horse, until they found a wild horse that Billy domesticates. They fall in love soon after and make love. Then they're found by the Sergeant and his men who were alerted of their whereabouts by the cabin owners. They beat-up Billy and tied him to a trunk, kill the wild horse, then proceed to gang-rape Flower, and steal the remaining horse.
After they leave, Flower releases Billy of his bindings, but when he separates from her temporary she commits suicide. Heartbroken, Billy buries Flower and searches for vengeance.
Billy follow the soldiers ambushing them in the middle of the night and kills them. After that he returns to the town willing to take the job his friend offer him in order to leave forever the gunslinger life. When he's leaving the place, he's shot by the owners of the cabin. In the final credits the footage alongside the lyrics of the song imply that he and Flower are living together in heaven.