In reply to the release of the SW500 by MTI, Karpatia released the 3927. Originally lacking the mass and strength of the Notum alloy frame of the SW500, the 3927 could be just as dangerous to the shooter as to the target. The 'Notum' finally solved this problem, while at the same time enabling the gun to be more widely modified. The Chapman was the first experiment at this.

In reply to the release of the SW500 by MTI, Karpatia released the 3927. Originally lacking the mass and strength of the Notum alloy frame of the SW500, the 3927 could be just as dangerous to the shooter as to the target. The 'Notum' finally solved this problem, while at the same time enabling the gun to be more widely modified. The Chapman was the first experiment at this.