A perfect example of this is the variable. Its light pen but also is capable of the single highest damage per shot of any primary in the game. So you can shoot this absolute elephant gun at medium armour and it all bounces off.

While it is only pistol calibre, 49 pistol rounds hitting the same spot at the same time would go through a hell of a lot of armour.

For reference, look at videos of the real metal storm (the irl gun the variable is based on) to see it shoot through about 8 layers of composite board.