I had some old military surplus for my 8mm Mauser that would hang fire, not ignite at all, and most would be ok. Damn that stuff gave me the flinches after a couple 30 sec hang fires :smiley_confused_sch! Took me three more times shooting larger calibers to get over it.
The first time it happened I pulled the trigger and nothing. I kept the gun pointed down range and waited...nothing. I go to pull the bolt back to clear it and BOOM! Bought needed a new pair of Superoos.
The rest of the ammo is in the bottom of the pond.
lol, i had a muzzleloader hang fire on my buddy once , funny as hell , because he just got the gun away from his shoulder bout an inch when it went of ,bruised his shoulder , taught him a lesson on never pull the gun from your shoulder till you know for sure its not gonna fire