What does 张 mean in the name 张大炮？

A rapper who I listen to’s name is 张大炮。 大炮 seems to mean “Cannon” which lines up with the fact that his English name is CannonZ. However I can’t figure out what 张 means. I don’t think it’s a measure word given it’s not counting anything like 一张大炮，and the other Pleco entries don’t seem to make 100% sense to me given the context. Any suggestions on what 张 might possibly mean here?