The Adam-ska Special was a specially customized AM D114 pistol with black frame and ivory grip, both of which were heavily engraved.
Background and features
It's statistically similar to the level 2 AM D114 pistol, excluding the ability of using a silencer. It was rumored to have originally been used by an infamous triple-crosser.
One Diamond Dogs soldier ended up using this gun during a live fire exercise, with Ocelot, acting on past experience, lecturing the soldier on how it wasn't necessary to reduce the recoil. He also mentioned that the markings didn't give a tactical advantage on the battlefield.
Behind the scenes
The pistol was first revealed as a Day One and Collector's Edition bonus for console versions of Metal Gear Solid V: The Phantom Pain. Its name is a reference of Ocelot's real name, Adamska. Its rumored owner being a notorious triple crosser in the description is a reference to Ocelot's treacherous nature in his previous appearances in the series.
In all retail versions of the game, the Adam-ska Special is seen in a cut-scene where Diamond Dog trainees are shooting at targets with AM D114's with Ocelot instructing them. One soldier is firing the Adam-ska special from his hip, and when it jams after the soldier attempts to pull a stunt, Ocelot explains to him that the weapon is an automatic and there is no need to compensate for the recoil, as well as that the engravings give him no tactical advantage in the battlefield; however, he does compliment the soldier on his "fancy shooting." This is a reference to the advice given by Naked Snake to a young Ocelot in Metal Gear Solid 3: Snake Eater, first after besting him in Rassvet during the Virtuous Mission, and then when encountering him in the same location during Operation Snake Eater.
The Adam-ska Special is a grade three weapon, and only requires 18 minutes of development, with no GMP or R&D team necessary.