Abstract: A one-shot weapon includes an external grip, a profiled receiver attached to the grip, and a supporting base hingedly attached to the receiver. A sleeve is connected to the supporting base, and a barrel is disposed in the sleeve. A firing block has a cube-shaped head mounted on a top part of the receiver and abutting against a vertical wall of the receiver. The firing block is interchangeable on the receiver and allows for annular or central firing. A trigger connected to the receiver is operable by a trigger tang. A barrel release connected to the receiver defines a trigger guard for protecting the trigger tang. The receiver has an adjusting mechanism for enabling adjustment of a trigger stroke. A safety mechanism is pivotably attached to the receiver.