ok saying you hit the magazine full of bullets, well there is nothing to set off the primers which are touch explosives chemically engineered to not detonate until x PSI thresh hold is exceeded. Some of those rounds may detonate the touch explosive but because the integrity of the round is not maintained by a steel tube the would just explode on impact, causing a small, fragmental, and marginally incomplete chain-reaction. maybe 10% of the cases may detonate, at the point of impact most likely. the projectiles are facing forwards so the blunt brass is unlikely to penetrate in reverse because it has far less mass than lead.