Some specific blocks of serial numbers of military .30-06 rifles are prone to failure during firing, especially with high power cartridges. Some old Mauser rifles are prone to failure. I don't know if the failure mode can harm the shooter or just ruin the rifle.


Old shotguns (here we are talking pre-1980 manufacture) are not suitable for firing with steel shot. They were designed to shoot lead shot which is malleable. Shooting steel shot in an older shotgun barrel may damage the barrel, though it would probably not result in catastrophic failure that would injure the shooter.