Good. I don't need my pistol emoji replaced with a squirt gun any more than I need the word pistol in this sentence replaced by my keyboard, my browser, my OS, my font, or anyone else who isn't me who wants to dictate how I think and how I express my thoughts.
Unfortunately, it's not "your" pistol emoji; it's someone else's, that you're reading on your device. And likewise, the expression of your thoughts is already controlled by the emoji font installed by the other person.
I also think it's a silly change that software vendors had absolutely no business making, but I am afraid that the battle is largely lost. All popular platforms now render the pistol as a squirt gun. Rendering it differently on your own computer achieves little.
Very strange that OpenMoji seemingly calls it a "water pistol" while continuing to render a revolver, however. That's surely going to annoy everyone...
Right. Everyone would complain if the message "squirt gun fight" where rendered "pistols at dawn" or vice versa. There's going to be ambiguity in any language, and to make it worse, most adults are not native speakers of emoji.