I was out at my parents new farm this weekend shooting with my brother.  I told him to bring some ammo with him if he wanted to keep shooting.  When he was done with his remington ammo I shot another magazine worth of the ammo that I brought.  When I was cleaning up brass later I saw a ruptured case on the remington 223 ammo that my brother bought.  I shined a light into the chamber and didn't see any problems.  Is this common?  I've had this gun six months and I have never seen anything like it. I've linked the picture down below.


Did we come close to blowing the gun up?  I put another magazine or two through after my brother was done and I didn't notice any problems, so is there nothing to worry about?  Any input would be helpful.  Thanks fellas.

Adam

Were they reloads?  I've had that happen a few times with my 9mm reloads (unknown round count on the brass).  I don't think it's a clear sign of "overpressure" or likely to damage the weapon.  The case simply failed.

Nope, my brother had picked them up the night before.  They were brand new from the box.  When your 9mm casing split did it damage your gun?

Not to my knowledge.  I've seen linear splits like that in the wall, some on the lips, and at least one around the base/head of the cartridge.  That's going to be against the chamber wall which is designed to take pressure anyway.  I don't see it doing any damage.  If it was factory new ammo and not reman'd ammo, I'd probably send the pic to the manufacturer.  They'll probably want to know the lot number off of the box.