The Akvasto is a dual version of the Vasto, a powerful and accurate revolver type secondary that offers a faster fire rate, double the magazine size, and lower recoil, while suffering slightly more spread and reload time.
The Akvasto has a high chance of cutting corpses into pieces, similar to Slash-focused melee weapons. This makes the Akvasto a prime candidate for a DesecratingNekros to bring along, as the game considers the cut corpses as separate entities, essentially giving multiple corpses to desecrate from a single enemy and thus yielding more chances to create more drops.
The reduced accuracy of the Akvasto is a byproduct of its faster firing rate. When pinpoint accuracy is required at a distance, consider pausing between shots to steady your weapon and allow for more consistent aiming.
With the right mods you can get Akvasto up to 32.20. If you do this it is recommended that you bind mouse wheel to firing (LMB can still be bound to it at the same time). This allows you to not be as hindered by its Semi-auto style, although at first it does feel a bit awkward.