The low brass was only 1oz of shot. The high brass was sellier & bellot full power buckshot, remington express 6 shot and remington mag 4 shot. I didn't measure the gas ports but a paper clip goes through all 4 holes and the puck is not stuck. It takes a fair amount of effort to rack the slide back after the hammer has been cocked. New out of the box it would not cycle the buckshot even on setting 2.