As near as I can tell, from my amateur photography attempts, Unclenick has described the best method.
I took the pick below just now, using the method Unclenick described. I didn't have the best light, but its fairly clear.
Having at least a 12 megapixel camera, a tripod and a macro setting are going to be the easiest ways to take clear, detailed close ups. Using a flash on close ups also doesn't work very well, at least not for me.
Random .308 Winchester case.