BIL had this happen on a .243 Rem 788..... he is not real religious in cleaning his guns, and used a heavy oil to lube it. Oil collected crud and jelled up in the cold, causing light primer strikes. Cleaned the bolt (inside and out) and used dry film lubricant. Problem solved.
TheGolden Rule of Tool Use: "If you don't know what you are doing, DON'T."