If you're shooting up deadwod make sure you aint lined with your finger on the backside. Trust me.
Or your thumb. Did the same thing you did when I built my house. Trying to toenail in some deadwood and the nail hit a knot and went into my thumb instead of the wood. Buried the 3 1/2" nail up to the head in my right thumb. My dad pulled it out with linemans pliers. Hurt much worse coming out than it did going in.