It doesn't look as if you used any kind of difussion panel between the light and the object. On highly reflective materials, a reflection line is not uncommon, but look at the copper tip of the bullet on the right. You have lost detail.
It looks like you have your light source is directly above. I would suggest to have it at ~135° and lowered plus have a reflector opposite. This would increase the amount of shadow coming forward in the frame and eliminate the reflection line. Having the reflector opposite your main light will bounce back the light onto the object.
Another suggestion? During the learning curve phase, choose objects that are not highly reflective. This will diminish the frustration factor. Once you are comfortable with controlling the light, then introduce more challenging projects. Just a thought.