 Hathcock's health began to deteriorate and in 1975 he was diagnosed with multiple sclerosis, and he was medically retired with full benefits and 100% of his pay just 55 days short of the full 20-year retirement requirement. Hathcock was honored by having a rifle named after him derived from the older semi-automatic M14 and named the Springfield Armory M25 Whitefeather due to his nickname.