Shrapnels of new shard bombs can go through barriers that should stop all bullets and prevent monsters from passing it. All other bullets, charges are stopping on barrier.
Shrapnels of new bombs can go through and explode on other side. This can lead to exploits where player hides behind barrier and kills monsters which cant cross barier.
And ironcially they dont go thru small obstacles that guns run over. Try the pots room in training hall.