Looking at a Belgium 16 ga with Belgium nitro proof and the brls say Cockerill-Stahl. On the side of each brl reads
Amtlich Vierfach Geprueft Und Einges Chossen
Mit Staerkster Ladung Rauchldsen Pulvers
I do not see a date code. Has a GCD on brl flats up near where the brls start.
Perhaps someone can interpret? Perhaps German brls.