Added a Normal map, might have adjusted the exponent very slightly.

Dont feel obliged to use the normal map - I've made it as an option. If some parts of it are too severe or not refined enough then it works fine as originally submitted (without it - note the base albedo has not changed apart from the bullet fix....)

Bullet is messed up by the (ingame) AO texture, but just incase this ever changes I've corrected the bullet in the base texture.