Well...it's a strikingly simple, graphic idea, which is very good.
But I am not so sure that seeing a sign laying on a bed of grass is really getting across the idea I think you are after. The arrangement is also a little too tidy, with everything nice and squared up with the cover's margins.
First, I think I would suggest not placing the sign on the ground. Second, I would suggest not making the cover so neat and symmetrical. At the very least, tip the sign at an angle. This will add a subtle sense of drama and of something being amiss.
I am not too sure, either, about the title and author name being so equal in size and weight.
And, yes, some bullet holes would help.
I guess my earlier reply has to be "approved" now before it's visible, no idea why...