The phrase "bust in" is often used to describe forcefully entering a room or a building. However, there are several synonyms that can be used to convey the same meaning. "Crash in" is a commonly used expression that implies breaking through a physical barrier. "Barge in" is another phrase often used to describe a forceful entrance. "Storm in" has a more aggressive undertone and suggests a violent, chaotic entry. "Rush in" is a slightly milder alternative that implies urgency and haste. It's important to choose the right synonym for the context to accurately convey the action being described.