Whenever you're near a wall or some solid object, and you use the blackhawk/silversix charge by a wall, the final projectile instantly explodes before doing anything if you're too close to a wall.
Solution: Add a timer until it CAN explode, or move the bullet spawnpoint.
^Actually, that would be somewhat incorrect, Hazel.
The bug is a result of a nerf largely intended for the Divine Avenger. Using the Divine Avenger, people could break through walls and manipulate the "puzzle" environments in a way not intended by OOO. This led for some fun and simple exploits such as breaking the wheels at FSC and breaking through ghost blocks from the other side of a wall.
Basically they moved the charge attack release from in front of the player, to slightly behind the player which causes it to collide with walls. This results in an obvious problem that may be never fixed but I'm glad to have yet another topic pointing out the ignored issue OOO created.
This is a bug as old as the game itself, and it will probably not ever be fixed. It's not exclusive to those weapons, either(DA Charge, Gran Faust, etc).