Approx. 10 years ago I bought at country auction a Crown grade 12 gauge, 32 inch barrels, straight grip stock, beavertail forearm that was marked on the water tables 3 in. or inch I disremember exactly. Anyway, when I got it home and studied it I noticed when I held it to my shoulder and the light hit the barrels, there was a distinct circle or raised area around where the 3 inch chambers ended. You couldn't see it otherwise but the light would catch it every time. So, to make a short story long, I sold it as it made me nervous. Later someone told me that it was probably rechambered and not a factory made 3 inch. Anyway, I have always been curious as to what I actually had. I have no idea how LC marked their 3 inch guns.