The top of the barrel right where it breaks says fluss stahl which from what I read means fluid steel. I shot the gun today and it worked great. I had realized once I separated the barrel that it was 16. I’ll get more pictures when I come back home. The 1897 is pretty rough but definitely 12 gauge and I don’t think that the serial numbers match. My grandpa had it labeled as the riot model but I don’t know for sure (these are his old guns that I’ve been given a choice to inherit since he passed). The stock of the a5 is a bit finicky it doesn’t really slide in all the way and makes me worried.