Glock 20, fifth round ever shot from firearm. Blew the magazine out the bottom and left a burn on my trigger finger. Only damage was to the lips of the magazine. The ammo was new and of the nickel casing type. It was a 180 grain full load (not subsonic). I fired the rest of the box without incident. I have since replaced the OEM barrel with a KKM barrel and everything works great. No Glock smiles, but I still resize with a Redding die.