I've used Hoppes #9 for 40 years in rifles, shotguns & pistols; buy it by the pint. Frankly, I use it first and then follow up with gun oil. Never had any rust problems doing it that way. It's a good product and smells good. Darrell
I recently bought an old Browning Superposed at auction. The gun was quite dirty, including the barrel. I got out the drill and attached my brass rod with the brass brush. Wetted down the barrel with Balistol and ran the brush up and down the barrel several times. Put through a tight cotton patch and had a look. Just in front of the chambers for about 10-12 inches the barrel was not shiny. I did it again. Not much change.
The deposit in the barrels looked like plastic wad gunk but I was not sure. I even thought it might be pitting and nasty corrosion. So I went to the stinky plastic solvent sold by Brownells. Nasty stuff. Harsh and caustic. Wet the barrels down good and got the drill going again. Ran that thing up and down many times. Ran the patches down the barrel and there was not much change. I had about concluded the barrel was pitted and I was out of luck.
Before I gave up, I went to good ol' Hoppe's No.9. Wet em' down and ran the brush through a few times. Put through the patches and had a look. Viola! Clean and shiny as a brand new dime.
I LOVE Hoppes. Love it. I finished off by putting a bit behind my ears and around my neck. Can't smell better than that. (Not sure my wife agrees.)
Colt had a problem a few years back with a problem of pitting on their nickel plated guns. Through their testing, they found that the Hoppes #9 was the culprit. I don't remeber the exact details (probably can be found on the web), that the ammonia was causing the pitting.
I have been using Hoppes #9 since I got my first real gun over 50 years ago and like many of you I find the smell wonderful. An old timer who shared his shooting knowledge with me when I was a kid called it Banana Oil. Everytime I open the bottle, that is what passes through my mind, Banana Oil. Does sort of smell like bananas, well to me anyway. gyrine
Yes, the ammonia attacks the copper plating under the nickel plating. Nickel won't adhere to steel so there is a layer of copper beneath it that will adhere to both metals. If the ammonia can get under the nickel it will attack the copper (remember, that is what it is supposed to do in the barrel) and therefore flake off the nickel.
Before SS became popular I had several nickel plated guns and I was always careful about using any ammonia based product on the nickel finish.
My wife says real men smell like Hoppes #9. That said, Hoppes will not corrode, but do not confuse it with other cleaners. I routinely leave Hoppes in the bore for 24 hours then wipe clean. Day after day until all the green is gone. I think it is an adequate rust inhibitor but not for extended storage. Their own instructions say to finish bore with gun oil to prevent rust.