As mentioned, the best lighting is outdoors on a cloudy day , avoid a white or very light background as it will fool your sensor and give you a dark
image,and the use of a large white sheet of cardboard flat/horizontal below the gun, but out of the picture, will bouce light up and eliminate a lot of shadow and can be used to highlight engraving on closeups.

Better to keep your mouth shut and be thought stupid,than open it and confirm.