The Blazing Trail (movie, 1949)

Old Mike Brady built Brady Town and was a leader, but a bullet from an unknown assailant has ended his life. When the will is read, it leaves the bulk of the property to Kirk, the gambling son of Mike. This upsets Sam, the hard working son, but not gambler Full House who always beats Kirk at cards. But even the Sheriff is suspicious of the will, but he needs proof and the Durango Kid will find the proof.