The CZ24 mags have triangular cross section. They are not a square box. The triangular cross section directs the rounds from either side towards the chamber. They feed from both sides at the top of the mag. Kind of like a Soumi mag in 9mm. Like the 9mm round, the mag could be curved to spread the spring force across more of the body of each round and improve reliability. The soumi straight mags in 9mm and the CZ24 mags work great with the straight profile. The guns were eclipsed by the AK47 and AR15 developments.