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.