The Squib Tool is used to remove stuck bullets from barrels of both revolvers and semi automatic pistols. The tool has a sliding hammer made out of brass for mass, a brass rod that is inserted in the barrel and pads on that rod to protect the barrel. When a squib round event happens, insert the brass rod into the barrel and use the brass slider to force the bullet back into the cylinder. The brass rod unscrews and this tool becomes compact enough for your range bag.
You need to be cautious as you remove the squib round. Keeping the revolver pointed in a safe direction at all times. If you can open the revolvers cylinder do so and remove the cartridges. You then force the squib round back into the fired case. The same caution applies to semi automatic pistols. Remove the magazine, maintain a safe direction and use the tool.