I have watched many videos of large but "amateur" (not military or NASA) rockets and I would have guessed that without some sort of stabilizers like gyroscopes or fins the rocket might wobble or show some other kind of major instability. However such rockets go straight and I am wondering if they all have in fact gyroscopes.
My own experience with model rockets is that they did have fins and bottle rocket fireworks had a long wooden tail that perhaps helped stabilize it. But for larger rockets that go many thousands of meters it does not seem like a gyro would be enough to combat the forces that could cause wobbling, etc.