I've found an old bullet (I'm told it may be French and WW1) with letter and numeral markings. The bullet is approx the size as a German 7.92mm but slightly longer.
There is a central letter "R" with the following 4 marks around it: "A." / "R.S" / "4." / "10"
I do have a couple of photos but have so far failed to put them up with this message. If anyone can ID the bullet and tell me what the marks mean I;d be very grateful. PM me if you need to look at the photos.