I can’t speak specifically to HC, but I found pistol and shield cadence to be the most depressing ranged option in game, only slightly above pistol and shield RF (and I assume Savagery), outside of stronghold set which gives enough flat to act like you are using a 2 hander and performs reasonably because of it. This is not necessarily a build critique, just an extreme weakness of the playstyle
Any reason you wanted to use the shield and not a second pistol?