I just tried some researching on L.A.'s weapon. It really is just used for cutting cheese and hardly used for murder. Wiki also pins it as a "fictional weapon". Plus, you can't do the stuff L.A. does with that thing. Perhaps i'm just looking at the wrong place...
As for Ricardo's revovler, it just seems rather bulky and i couldn't recognize it as a Colt .45
Then it may simply be a case of dramatic license.
I blame it on LA being a witch and turning strings into deadly weapons being one of his powers.