I met unscrupulous teammates at the beginning, watch me turn the tide

The world of famine escape is a world as its name suggests. And I was transported into such a world. At the beginning, I was abandoned by my teammates to die. But it doesn't matter, I have my own system. After upgrading once, the damaged pistol can hit teammates. After upgrading twice, the bullets in the pistol have an explosive function. In this era of universal mutation, I am a breath of fresh air. ...