Got more information today on FN. Full name on concave rib, Fabrique Nationale D'Armes De Guerre Herstal Belgique. Serial number 6125 has assisted opening, chopper lump barrels, auto ejectors. On barrel flats D= 65mm over 20.5. So it is 2 1/2" chambers. What does the 20.5 stand for? Also on barrel flats P1 436, K over P.V. Chokes 183
?, but there are other symbols there I couldn't make out. Plus there were more synbols on barrel flats I couldn't identify. Rounded pistol grip, and at least 22 lpi checkering.
Blue Book of Gun Values only listed pistols and rifles.
As I stated before any informaton would be greatly appreciated.
Thanks, David
