The MAG-7 is an unusual shotgun made in South Africa in the 1990s, and imported to the US in small numbers. The idea of the gun was to offer maximum firepower in the smallest package possible, and to this end the gun had no buttstock and a 12.6 inch (320mm) barrel. It was chambered for 60mm 12 gauge shells, feeding from a 5-round detachable box magazine in the grip of the gun.
Unfortunately, importation into the US required modification to the gun to avoid it being classified as an NFA "short barreled shotgun" or AOW. This entailed extending the barrel to about 20 inches inches (500mm) and adding a wooden buttstock. These changes utterly defeat the purpose of a small and concealable shotgun. In addition, the stock design is quite poor, and has a comb so high that getting a sight picture is very difficult.
The general handling of the MAG-7 is also rather poor, in my opinion. The grip is quite large to accommodate the box magazine and the gun is bulkier and heavier than one might expect from photographs. The pump itself overlaps the trigger guard, which results in the shooter smacking their trigger finger, should they index it on the trigger guard which cycling the gun.
The final strike against the MAG-7 in the US is its use of 60mm shells. These are not in general circulation in the US, and can be very difficult to find. A handloader could certainly form their own shells, but this is not a common practice. The oft-cited alternative of using Aguila 45mm minishells is not practical, as these shells are too short to cycle reliably.
Given the choice, I would take one of the Cobray Streetsweepers over this thing.