By using the quill screws it is pssobile to direct the gunpowder gasses when leaving the muzzle. Therefore, it is possible to correct the movements of the muzzle at firing.
Start off by placing one or two screws in the opposite side, to the side the barrel moves when firing. If the muzzle simply moves straight up and down then the first quill screw should be placed pointing straight down. This will cause more gas from the gunshot to be directed upwards and to the sides, thereby reducing the upwards motion of the muzzle.
NOTICE: Do not screw in more than one or two screws at a time. If more screws are inserted at once, then there is a risk that the effect will be so large that injury can occur, e.g. bruising from the gunstock.