"Neither do we agree that the testimony of the ballistics expert was inadmissible. The weakest part of his testimony was that he could not identify a bullet as having been fired from the pistol found in appellants' vehicle when they were arrested. However, he did testify that it was from the same type of weapon which was found in appellants' vehicle. We think this is corroborative of other testimony and it was proper for the court to allow the jury to hear it. Again, it may be of little probative value but, nevertheless, it was not improper to allow it to be considered by the jury."