It can just about take a finger off if you’re not careful. As you put it together, the last centimeter or so it will go into a self-sustaining implosion. There’s not really much you can do to stop it. Keep your fucking fingers clear if you want to keep them
Sometimes it helps to put a rag or cloth in there so the can smashes down onto the cloth and has a soft landing, then carefully pull the cloth out. Dry kitchen rags work great for this.