The .357 Joker is a revolver.
Behind the scenes
It is one of the only Unique weapons found in Tom Clancy's Ghost Recon Wildlands that doesn't have a standard version, with the only others being the Wilderness, Ice Shard, The BFF and Stampede; and can only be purchased through the in-game store. The name implies it is chambered for .357 Magnum, giving it high damage output and is embellished with engravings on the frame and barrel.
Gallery
Side view of the .357 Joker.