That primer would have had a cardboard box between it and what ever hit the primer and so would the nose of the bullet. That would be pretty good protection for an accidental blow. Likely why ammo is shipped in boxes and not loose.
Looks like the bullet was sitting on something rough and hard, that dented it and gave the round the support that it needed for a strike on the primer, to set it off. I believe a different story is involved from the one that was told rockinbbar. Just an opinion of someone that has picked up a lot of boxes of ammo over the last 57 years of shooting.
Any body else ever had a round go off when they picked up a box of ammo?
