Found a better trick for firing only one bullet/shell with the Carbines and Mace.
So I'm aware that swapping to a different weapon as soon as you pull the trigger interrupts the second (and third, in the case of carbines) round and stops it from potentially wasting ammo, but did you know that swapping to an empty weapon slot does the same thing without changing your weapon?
Thought that was cool enough to share, considering it means you can use Carbines to effortlessly dismantle the groups of exploding bastards with extreme efficiency and immediately fire the *second* shell from the mace if the first doesn't do the trick.