Polishing out minor scratches on silver nitride finish

A. The nitrided surface is very hard, so You'll need some sort of abrasive like Scotch-brite. Unless you have lots of experience, you'll likely make it worse. I'd suggest you ask a gunsmith to do it, or send it back to Browning.

A. Nitriding is a very hard surface treatment for steel. If effectively done, it is very unlikely to get scratched. It is also too hard to polish with domestic products.

Nitrided steel may be "silver" coloured but there is no silver metal involved in the process.

Just for the record silver nitride does exist. It is an uncommon and rather nasty explosive!

A. I did warranty for Browning for over 12 years. The plating is a form of nitrating but silver really has nothing to do with it. It's just silver colored. The finish is extremely hard but be forewarned that it is less than .002 inch thick. Rubbing it to much with an abrasive even as fine as 1200 weight wet and dry paper or crocus cloth is like trying to buff out a scratch on your car with a belt sander. By the time you even think about starting you have already made a horrible mess. I personally would not touch it on a bet. I have seen a lot of people try and it ALWAYS ends up a disaster.
Sending it back to Browning to be re-plated is your only option for refinishing. A customer of mine brought in a silver pigeon to redo and I apologetically showed him the other side of the door.
He took it to a professional plate shop that did a lot of table wear and metal statues for the artsy fartsy people and had it nickel plated. It came back pitted from the plating operation and for what ever reason the nickel did not adhere well inside the engraving and began to peal at the edges in under a month. On top of that I had to ream all of the holes so that he could get the pins, top lever and ejector trips back in.
He wanted me to approach the plate shop on his behalf and get them to redo it. But, I declined and informed him that what I knew about plating could be written on the back of a 22 shell with a four inch paint brush. Which by the way is the truth. Besides, he took it to the plate shop and it was not my idea. There was no way in hell that I was going to get caught in the middle of that range war!
In my opinion plating is for car bumpers and bluing is for firearms. The best advice I can give you is just ignore the scratches and use it or trade it off. The Citori is still one of the most well designed and reliable DBL shotguns ever made.

A. I used Hagerty Silversmiths Polish =>
out of Indiana and it really brightened the finish and took care of some blotches from handling my SKB Model 600 28 ga over the years. It may not help with scratches but the bright surface will make them less noticeable. Tom