On January 14, 2004, about 1526 mountain standard time, a Cessna 305A, N305BD, ground looped during landing rollout at the Casa Grande Municipal Airport, Casa Grande, Arizona. The airplane was owned/operated by the pilot, and it was substantially damaged. Neither the airline transport certificated pilot nor the passenger was injured. The flight was performed under the provisions of 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated about 2 hours earlier from Blythe, California. The pilot verbally reported to the National Transportation Safety Board investigator that he had recently purchased the airplane, and he was in the process of flying it to his North Carolina home. The pilot indicated that the wind was nearly calm when he landed on runway 05. However, upon touchdown the airplane bounced. During his recovery, he lost directional control when the airplane began swerving. In the pilot's completed "Aircraft Accident Report," he described the sequence of events leading to the accident in the following manner: I made contact with the runway in a three-point configuration, but I was not in a full stall. I ballooned into the air about a foot coming back to contact the runway in a full stall three-point landing, but with the nose of the aircraft about 10 to 15 degrees off to the right. It felt as if the right wing stalled a fraction of a second before the left wing, causing it to swing. This may not be what happened to the wing. While I was trying to straighten the aircraft with the left rudder and a short burst of power, the right wheel got off into the sand causing a ground loop to the right. The pilot subsequently indicated to the Safety Board investigator that the accident touchdown had not been perfect, but it was definitely not hard. After touching down and observing the airplane begin to swerve, he applied full left rudder in an effort at regaining directional control. However, his effort was unsuccessful. When the pilot completed the Safety Board's "Aircraft Accident Report" he indicated that no mechanical malfunction was related to the accident. However, following the airplane's subsequent examination the pilot verbally reported to the Safety Board investigator that one of the airplane's tail wheel rudder control springs was broken. The pilot also reported that he has over 4,000 hours of accident and incident free piloting experience in tail wheel airplanes, with over 400 hours in a Cessna 305A. He reported a total pilot time in excess of 28,000 hours. The airplane was manufactured in the mid-1950s.