Sometimes you'll get resonance out of a firing pin spring, but if you're hearing ringing, then maybe you've got something metallic touching your barrel, like a scope bell maybe.
Sat watching TV one afternoon firing off primers with the rifle muzzle stuffed into and old cushion.
No bang, no flash & not enough grunt to light up the wadding.
Can't find that book, but grandma Google helped me out:
https://www.google.com.au/search?q=leade&ie=utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&dcr=0&ei=m0COWqL1O-Hc8wfrxI-IDg