The Mateba 6 Unica Autorevolver looks like something from a sci-fi movie, but it is an excellent handgun in this author’s opinion and a remarkable example of firearm engineering. It works by sliding on rails on the grip frame, using the force of recoil to cock the hammer and advance the cylinder, giving it a sort of hybrid semi-automatic revolver function. The barrel is aligned with the bottom of the cylinder, lowering the bore axis and suppressing muzzle flip as well as adding accuracy to this unusual design.
It is a very powerful weapon, and its high damage and ROF are a big advantage at close range where headshots can be very effective. However, the lower recoil does reduce the capacity, and at longer ranges it is not as easy to fire consecutively, so the reload speed and cyclic rate must be taken into account.
Another issue is that the cylinder can only be opened when the hammer is not cocked, which can be a problem for competitive shooters where it adds a half second or more to the time required for reloading, though it is probably intended as a safety feature. The upper slide assembly is blocked by a retaining screw, which makes field stripping more involved than with modern self loading pistols, but it prevents any powder residue from getting into critical areas like the trigger/release mechanism and the slide rails. Those who use their mateba autorevolver for hunting, defense or other non-competitive applications may find it easier to simply swap out the recoil spring for one designed to handle lighter cartridges such as.38 special,.44 magnum or.454 Casull.