1.) I found a 7.92x57mm with an F N 40 headstamp. I know who the manufacturer is.This cartridge is a little different and has a red primer annulus, a reddish-purple ring at the end of case neck and what looks like the remnants of a reddish-purple ring around the bullet tip. The bullet is a cupro-nickel FMJ type.
2.) Got another one with a green primer annulus and green ring around the bullet-case neck area headstamped F N 54.
Do these colors have any significance?
Thank you for any information provided.