Who cares if he shows a G21 kb! Look at what is said:
The photos below illustrate a catastrophic failure of a Glock 21. Again, this incident did not happen at Front Sight Firearms Training Institute, but is one of many reasons why Front Sight has always required students to use factory, new ammunition. The shooter of this pistol was using reloaded, full metal jacket ammunition. To the best of our understanding of the incident, the cartridge case was not sized properly, preventing the action from locking up fully, but allowing the action to close enough to fire the weapon. The result was an open breach detonation of the cartridge. The photos speak for themselves. The shooter received severely bruised hands, with minor to moderate lacerations to his hands and face. We have received reports of similar incidents with the Glock 21 and I have personally witnessed a less dramatic incident with a Glock 21 magazine blown out of the weapon and shooter's hand bruised. In all incidents reported, reloads were used." - 'Naish Piazza