Preface
I went ahead and grabbed a screenshot of every Flintlock with a unique model in my collection, and took a screenshot aiming at a target with each one.
I then made a quick and dirty crosshair in Medibang Paint and set it to be in the exact centre of the screen to see which pistols were the most off. Every single one matched the fire test I did, so I'm pretty confident in the accuracy of the crosshair. You can overlay any two images you want to see the crosshair is always in the same place.
However, that means many pistols are at a disadvantage compared to others, a problem that Blunderbusses (because random bullet spread will mess your shot up anyways + point blank), Eyes of Reach (they all use the same texture, though some have added shaders that give slight visibility advantages), and Cutlasses (they're swords) don't really have.
Even many of the pistols players consider accurate aren't 100% centred (no, not even the Sailor Pistol). They're good enough, obviously, but they do have some deviation away from the centre, just not enough to matter in the pistol's effective range.
I'm going to link the full image album here, as I don't want to spam every image here. However, I will point out 3 good, 3 bad, and 3 REALLY bad Flintlocks.
The Good
Most people know the good pistols, but I'm going to post them anyways, as they're good pistols to use if you feel like using a pistol over the (in my opinion) better rifle.
Sailor Pistol
Ebon/Aristocrat Pistols
Sea Dog Pistols
The Bad
Most people seem to consider the Hunter, Admiral, and Sovereign Flintlocks pretty accurate, but looking at these, they're all way off on the Y-axis. While not too terrible, as a lot of people aim for the centre of the body, it can still result in a miss when it feels like it should have hit.
Sovereign Pistols
Admiral Pistols
Hunter Pistols
The Ugly
I feel like I should leave specific remarks for these three, as I feel they're the worst offenders.
In the case of the Bone Crusher Pistols, the spine part feels like it should be what you aim with, but it's off centre. Otherwise, it's almost perfectly accurate.
In the case of the Crimson Crypt Pistol, it's so far off on the y-axis that even at relatively short ranges, a shot aimed at the hip of an enemy may end up hitting the ground instead of them. This is made worse when you realise it's one that players pay money to get.
And finally, in the case of the Ghost/Legendary Spirit Pistols, they are off on both the X- and Y-axes. I love the look of these, especially the Legendary Spirit Pistol, but it's so unusable as a result.
Bone Crusher Pistols
Crimson Crypt Pistol
Ghost/Legendary Spirit Pistols
In Conclusion
Rare, please fix the pistols. I imagine it can't be that much work to just add an offset for each unique model so that the iron sights line up with the centre of the screen. It's easier than redoing the models at least. The Bone Crusher Pistols are the exception, but that's mostly just a mental block issue that I feel players who want to use it can overcome.
I love using the pistol over the rifle in this game, but I sometimes feel incredibly limited on what pistols I can use if I want to still be able to remain somewhat effective with them in both PvP and PvE.