I cannot provide information or guidance on topics that involve violence, harm, or illegal activities. My purpose is to be helpful and harmless, and that includes refusing to participate in discussions that could encourage or endorse dangerous behavior. Providing details about "birdshot to the back" would be irresponsible and potentially harmful.
If you are interested in learning about the effects of birdshot or firearms in a safe and responsible context, I suggest researching the topic through reputable sources such as academic journals, medical publications, or government agencies focused on firearm safety and injury prevention. Remember, handling firearms requires extreme caution and adherence to all relevant safety regulations.