What is a main symbol of violence in this book?

mostly black and made of stell hot bullets but cool smoke arising the air signatured smith and wesson symbolized as a gun. many scenes of mice and men reminds me of the gun violence in my area of town, like that time when George and Lennie or when that innocent dog was shot and killed guns been a factor that effects us all in a way weither if its used during hunting or just raw cold hearted violence.