A pistol with a frame, a slide which is movable thereon and a rotary barrel which is located in the slide. The rotary barrel is rotated and moved axially with respect to the slide between a locked position and an open position by means of cams and grooves. In order to avoid the wear which is customary in weapons of this type, the slide is provided with a stop surface running obliquely with respect to the bore axis, and the barrel has a corresponding contact surface. During the locking by the flat contact between said surfaces, the beginning of the relative rotational movement is initiated. By virtue of this precisely guided and directed interaction, wear can be reduced by orders of magnitude relative to the prior art.