A firearm suppressor mounting device has a device body, a clamping element connected to the device body, a muzzle element adapted for connection to the muzzle, the muzzle element defining a first threaded portion, and the device body having a second threaded portion matable with the first threaded portion, such that the device body may be rotated and moved from an attached position and a detached position, the muzzle element having an engagement surface, the clamping element including at least a movable engagement element registered with the engagement surface when the device is in the attached position, and the clamping element being operably engaged to the engagement element to move it between a locked position in which the engagement element is biased against the engagement surface to prevent movement of the device to the attached position, and an unlocked position, in which detachment of the device is enabled.