N1725V

The airplane sustained substantial damage as a result of a hard landing. The pilot reported that he flew for about one hour and then returned to the airport to do three night stop and go landings. He reported that after the first landing he felt the "landing gear begin to shimmy." He did another stop and go landing. He felt the landing gear start to shimmy again during the rollout so he taxied back to ramp and shut the airplane down. He did a visual inspection of the nose wheel and did not see any damage. An inspection of the airplane revealed that the firewall was buckled and there was a flat spot on the rim of the nose wheel. The fixed base operator reported that maintenance had been performed on the airplane before the flight and no damage was observed to the firewall or the nose wheel.