Yup!! Are with August. A sudden onset of Miss-Fire is usually indicative of throw-by. I would guess, one of two causes as well. First is a peening of the sides of the locking bolt slots causing the bolt to pop up. Second is a peening of the leading side of the locking bolt, allowing the bolt to pop up. Ok, third ... a combination of the two. OK OK, fourth, a Trigger/Bolt spring going Tango Uniform. There is
also the "All of the Above."
Also inspect your fired cases for evidence of two firing pin strikes, one of which will be off to one side.
Coffinmaker