4 for Texas (1963) on Netflix

Sharpshooters Zack Thomas and Joe Jarrett are in a Texan stage-coach and manage to fight off Matson's robber gang, so afterward they can fight over the $100,000 cash carried by a railroad official. Both make it to Galveston, where each, including vexed Matson, meets up with respective accomplices in various dirty schemes. The money keeps changing hands and the scene shifts to a river boat, which should multiply the winnings as a casino, but the crooks and bullets follow.