1. The loud noise that is made when you open 24 oz. size Monster Energy Drinks by twisting them with the plastic seal still on. It sounds like a fucking gun went off.
2. The actual act of opening said beverage. However, you have only "busted the bronco" when the aforementioned noise is made.
This is homeless-speak that is relatively common to lowlifes and homeless people in the Southeastern Michigan area.
"Hey, shitfucker! You wanna bust a bronco with me? I'm so tired."
"Me too, Dave. Your cock sure did wear me out last night..."