The model 91 shotgun, is a gun chambered in 7.62x54mmR . It uses a unique, flat-head cartridge, so it doesn't move the rounds in the magazine while recoiling. The gun has standard front sights, but an adjustable rear sight. The rate of fire is about 70 rpm theoretical, and it has a 5+1 round magazine, which is loaded from below the reciever.
The photo shows the gun while the lever is open, and how the ammo is in the magazine