Did it myself just this weekend. I was at the range with my son. I was shooting my Contender in 45-70 with a muzzle brake. He had asked me something and i had popped one side of my muffs off to understand him. Needless to say, that after runnin my yap. I had forgoten what i did. I let fly with a 405gr HP out of that beast. I've had my ears ring before. But never did it hurt like that.