tell him take the gun to a GOOD gun smith to have removed and inspected
just tell him to call in advance and let the smith know the situation, so he doesn't just go walking in with the gun in tow!
I have seen this happen with reloaded ammo, but honestly never on a brand new factory ammo
my question would be did he BUY new reloaded ammo someone did for him, or from a bulk ammo shop that sold reused brass and just called it NEW AMMO, which is actually normally called and sold as
re-manufactured ammo,
so it was actually reloaded and thus could have had a bad one slip out the door causing the issue
I have also seen POOR loaded ammo, stove pipe a round in the barrel, shooter never KNEW it, due to they were new shooters and or heard it go BANG< and thought nothing about it till next round doesn't either feed load right, and or causes some other issue, bulging barrel, broken frames, mag wells and so on
for safety sake, here I again, strongly suggest he takes gun to a GOOD smith, to have safely removed and gun inspected, a GOOD smith might even be able to measure round afterwards and tell WHY it happened!
better safe than sorry here IMO!