Curse of the Undead
(1959)

In an old western town, young ladies are dying mysteriously from blood loss.  The doctor is also dealing with a neighbor, named Buffer, who is blocking a stream, cutting off water to the Carter ranch.  While returning from the sheriff, the doctor is killed.  The doctor's son confronts Buffer, and is killed by Buffer.  The doctor's daughter, Dolores, hires Drake Robey, a stranger in town, to kill Buffer.  When the sheriff tells Dolores to get rid of Robey, Robey follows and kills the sheriff.

Preacher Dan has a wood button with a cross on it, that upsets Robey.  Robey begins to slowly drain Dolores of blood at night.  Searching for Dr Carter's will, the preacher finds the diary of the previous owner of the property.  That owner's son, Drago, murdered his brother and then committed suicide.  For his crimes, he is now undead.  A picture of Drago reveals that he is Drake Robey.  The preacher wants to open all the coffins in the family crypt, to find Drago.  Dolores, under the sway of Drago/Robey refuses.  The preacher heads to the county seat to get a court order allowing him to open the coffins.

Drago/Robey shows Dolores the old map of the property.  The stream Buffer is blocking is on the Carter property.  Robey confronts Buffer with this map.  In a shoot out, Drago/Robey kills Buffer.  He then heads to the courthouse to stop the preacher.  Drago and the preacher also have shootout.  The preacher's bullet hits Drago in the heart.  Drago collapses and turns to dust.  The preacher retrieves his bullet, the button with the wooden cross is embedded in the tip of the bullet.  

Thanks Joseph C