Can you explain to how this takes away the +1 from aiming? Because I don't see it.
If a model attacks with this weapon after making an Aim action, the weapon’s Short range accuracy modifier is used even if the target is within the weapon’s Long range.
If you replace aim with short-to-long-range modifier swap, then it needs to say "instead of aim bonus" or similar. Also, if you spend credits to replace one modifier with another, the other modifier must be better (+2) and at the same time not have positive long range modifier. Otherwise it is useless compared to simply using the long range?
With that logic, it is only ever useful for the following:
Archeo duelling pistol, Needle pistol (with ammo and other variants), plasma pistol (low), stub gun (with ammo and variants), arc rifle, blast carbine, sawn-off shotgun (with ammo), Shotgun (some of the ammo), sling gun, suppression laser (broad burst), needle rifle (with ammo), plasma gun (low), rad beamer (focused) and yu'vath puzzle box.
That's a weird collection of guns.