A year after The Danny Thomas Show ended, Hamer reprised the role of Rusty Williams in the reunion special The Danny Thomas TV Family Reunion, which aired on NBC. On December 27, 1966, Hamer underwent emergency surgery at Santa Monica Emergency Hospital after sustaining a gunshot wound to the abdomen when a gun he was carrying in a shoulder holster slid out, fell to the ground and discharged. Hamer was carrying the gun after having just returned from an overnight hunting trip. After recovering, he appeared in a second reunion special, "Make More Room For Daddy", that aired during a segment of the NBC anthology series The Danny Thomas Hour, in 1967. Throughout the mid to late 1960s, Hamer continued to attempt a transition into adult roles and, according to Danny Thomas, enrolled in acting classes, but was unable to land any acting jobs. By the end of the decade, he had grown increasingly bitter and depressed over his waning career. To support himself, he began working for a messenger Service in Los Angeles and later worked as a carpenter's apprentice. Hamer's only post Danny Thomas Show acting role was a guest spot on the CBS sitcom Green Acres, that aired in November 1969.