it is supposed to be a bullet sitting in the bolt face.
that will probably be too much detail for a sticker, especially a small 3" 2D sticker on a vehicle moving a a decent speed. I think the headstamp with a small amount of lettering or just 5.56 on the bottom would be pretty simple and much easier
All I have in this world is my balls and my word and I don't break em for no one.