Red Dead Redemption Episode 10: On Shaky's Ground

"After John stops Irish from robbing two nuns, he finally reveals to John that his contact Shaky knows where they can get ammunition for the Gatling Gun. When they arrive at Shaky's warehouse, through the door they hear the sounds of Shaky being roughed-up by some goons. Marston must rescue Shaky and fight his way to the ammunition stores."