I suppose that depends on where you live.

Someone who lives in the Southwest won't need the same level of protection of someone who lives in LA (Lower Alabama), and that is probably different if you live within 500 yards of saltwater, even if his/her house is air-conditioned...

I live on the gulf, so pretty much anything that isn't at least parkerized will start to rust after 2 days

I have yet to see an AR lower/upper receiver rust. It seems to just the barrel and/or bcg that is the most vulnerable to rust.

The upper and lower are anodized aluminum and are incapable of rusting. Rust only forms on iron based materials.

Aluminum corrodes but because AR15 uppers and lowers are anodized it is near impossible for them to corrode unless the entire anodized finish is removed and left unprotected for a long period of time.

Living  and working within 3 miles of a body of salt water and within 9 miles of the Atlantic Ocean I do not see major rust issues on parkerized parts when stored indoors; blued parts and some melonited parts are a different story.

It seems to me that smooth parts tend to develop rust if they are not regularly oiled even with high quality finishes like nitride and melonite. Having said that I have seen parkerized Remington 870’s covered in surface rust. Most of these guns are always in the trunk of passenger compartment of a vehicle and I can say with absolute certainty that they are not oiled on a regular basis. I would not qualify storing them in a vehicle as being the same as storing them inside a house but they are at least somewhat protected from the elements. Also, the Parkerizing on these guns is pretty worn.

I am originally from South East Kentucky. I have seen firearms there that were stored indoors for their entire lives, covered in surface rust. However, none of none of those were parkerized and from the looks were never oiled.

I think it comes down to how the firearm was treated when it was put away. Surface rust will still develop on a blued gun even if it was wiped clean after handling; a light coat of oil has to be applied. Parkerized parts do not seem to suffer as bad but this may be to oil being trapped inside the pores.

Any oil that lubricates will provide some degree of rust protection and any oil designed to protect will provide some degree of lubrication. Because I regularly inspect my firearms for rust I use what I think offers the best lubrication. Surface rust can be prevented with regular maintenance but preventing internal damage from poor lubrication requires constant reapplication during use. Minor surface rust can be wiped off and at most it is unsightly but damage due to poor lubrication is an issue that can only be solved by replacing parts.

Unless someone started making alloy steel upper and lower receivers, they won't rust.  But they are only a few of the parts, a majority is steel.  The pins, the FA, the bolt carrier group, barrel, FSB, all of the LPK.

When I lived in Alabama and the Florida panhandle, if you weren't careful, during the summer, you could get a light rusting of fingerprints on blued steel parts, phosphated surfaces usually did not have a problem.  Yes, we had A/C.

I haven't ever seen it on an AR, but if corrosion gets under the anodizing it can bubble it up...

Not really, i do have a Chinese sks with barely any finish on it, and it will develop rust after awhile


And Remington express 870's will rust no matter what

Ive never had a gun rust inside my safe, but inside my house, (Usually 74°) yeah

 I live about 20 miles from tidewater, but the bores of rifles and shotguns stored in my gun room will rust if left unattended for prolonged periods. Relative humidity inside my house is typically in the 65 to 75 percent range.

My current practice is Kroil for cleaning, Slip 2000 for lubrication and Breakfree Collectors oil for rust prevention.  No one product serves all three applications well.  For rifles and shotguns that will not be shot and cleaned regularly, I leave a light coat of Breakfree Collectors in the bore and plug the end with a patch.  For the frequently used rifles and those with "stainless" barrels, a residual amount of Kroil provides sufficient defense against rust.  A light coat of Collectors is SOP for all the exteriors. - CW

If you want to use Froglube I suggest watching this video. Here

You should look into Eezox. I think it's pretty much acknowledged to be the best preventative product currently available. It is fantastic stuff.

Wow! I gotta say I'm very surprised. Seems like an objective, well conducted experiment. I'd never claim that Eezox was the top performing cleaner/lube, but I've seen a lot of similar testing done by home experimenters on different boards that almost universally coordinate with Eezox as a top rust preventative. I've used it for a few years now on guns and knives, and thus far had excellent results. Very interesting to see an independent tester obtain a different set of data in support of other products as superior. I wonder when the article was written, as I do believe most of the testing I've seen is probably a few years old anyway and could well be dated.

Appreciate seeing this dissenting data- just goes to show there are very damn few absolute truths in the shooter's world...




EDIT: Thought I'd add some of the data I was familiar with just to demonstrate I'm not completely out of my mind...

http://www.thegunzone.com/rust.html

http://www.6mmbr.com/corrosiontest.html

http://www.theopenrange.net

http://www.bladeforums.com/forums/showthread.php/1057567-a-not-so-little-rust-prevention-test-round-2

http://www.ctmuzzleloaders.com/ctml_experiments/corrosion/corrosion2.html

http://americanlongrifles.org/forum/index.php?topic=27169.0

https://www.slip2000.com/downloads/Corrosion_Analysis.pdf

http://thefiringline.com/forums/archive/index.php?t-508243.html

Although, only a few of these are as comprehensive as the test you've posted here. Again, very interesting to see an experiment resulting in different results.

If you handle it/touch it - wipe it off with an oily rag.  My dad taught me that over 40 years ago and it's still true today.

A rusty fingerprint?  It's your fault.  Wipe it off, put it in the case and don't handle/play with it without wiping it off again.

My dad's M37 Ithaca has almost all the bluing worn off from the middle of the receiver to about a foot down the barrel/magazine tube.  It looks chrome/nickel plated - but there ain't no rust on it.

I still wipe down my parkerized guns.

Oh, 3n1 oil for about 35 years and lately either 3n1 oil or Mobil 1.  Either seems to work fine for me.  Blued guns, stainless steel guns or parkerized guns.

Weapons Shield has serverd me well for years as a CLP, works more better than fp-10.

eezox has been my best rust prevent for working firearms.

long term storage non use  cosmoline.

Hoppe's has never failed me.  Y'all keep using that new stuff...

My Dad had some old rifles he had as a kid (1938 and 1940, I think) that we kept in the attic over our garage in New Jersey year round.  We'd wipe them down with gun oil before putting them away and they look fantastic.  They were up there for 35+ years before I moved them.  I have them in a safe with Goldenrod/desicant now, but non-climate controlled area in Florida (and always wipe down metal parts with an oily patch/rag)

Also, we didn't shoot a lot.  Probably only used (and susequently oiled) them once a year or every other year even.

I think ANY oil will keep guns from rusting (a nice light coating).  All the internet tests are with salt spray and/or leaving the metal outside in rain etc.  Unless you keep your guns in the rain, I think any oil will protect them well.

Sure, the better oils will protect better, but unless in extreme circumstances it probably won't make any difference.

Up here in the winter every time you come in from the outside and your firearm starts to warm up to room temp it's like you just picked your gun out of a bathtub, thats when they rust inside and out, so i am always looking for something better, froglube dont cut it, it turns to crud and your guns action wont work.
I usally use 3in1 or mmo or even wd-40 because i use whatever i have around as soon as the gun dries out. Looks like wd is not such a bad product.

As far as exterior rust. The Ar platform really doesn't have much that can rust. So any excess CLP that is on the gun after cleaning is probably enough.
But something like a nice blued Winchester 92 that's another story. The "Blued" finish if left with no oil or finger prints on it will rust in short order.
What I leaned from a friend that did Civil war renactments , sometime outside in a down pour, is to use Birchwood Casey's Barricade.
All my guns get cleaned and oil ( Usually Breakfree CLP) and then a light spray on the outside of Barricade and a wipe with a clean dry rag and into the vault it goes.
I have been doing this for 20 years and never open the vault to any surprises. The Barricade lasts along time. I recoat every about every six months, maybe a year longest. If the gun hasn't been used.
So this is for the average shooter that takes his guns out shoots them, cleans them and then stores them.
Somebody like a hunting guide will want more protection. The gun wiped down with Barricade on a  daily basis. Or a a dry gun with a application of a car wax, like Turtle wax every two weeks.
Stainless would also rust if this wasn't done to it. So maybe a person outdoors this much would be well served with one of the "Shake and Bake" finishes such as Cerakoat or Duracoat.

When i was moving around.....

I left a safe full in a garage for a year Denison Tx (north of dallas).

Everything was oiled when i put them in i'd never had rust issues in the house. Everything rusted from AR's , fal's , ruger super redhawk , stainless colt 1911 , stainless springfield 1911.

Most was just minor surface type rust........ springfield 1911 that barrel was rusted beyond my comprehension.

Having spent the last 30 or so years on and around Navy ships I can say that rust will in places you never thought of.  Even areas not subjected to direct contact with salt water.
It really does never sleep.
All the shipboard crew served and small arms are maintained with good ole CLP...
Preparation in my opinion is more important than what preventative oil you use.  You have to get all the salt, dirt, water and mung off before you apply the CLP, just like panting.  You can buy some time hosing down your rifle with CLP a range trip but eventually rust will start somewhere...I swapped a couple of flash hiders a while back I found a little rust stating on the muzzle under the flash hiders even though they stayed wet with CLP unless I was shooting.
 

I have used Breekfree Collectors for several years. It's really good. My firearms was in the basement for 5 years and not an issue....WD

The Soviets didn't know his name but Mattias Rust shot a big fucking hole in their low altitude radar net .   Scared the shit out of them because they knew we knew they were sitting ducks to cruise missiles.





Yeah, he was no ordinary German teen.  He had a handler, probably his CFI
Oh, you mean iron oxide...protection from corrosion is primary, firearms are lubricated by boundary film so nearly anything oil works, at least for a while.  Have lube and reapply if you are in tactical burden with ammo and expect to fire hundreds of rounds.  For self defense concealed carry, cleaning once a week an application of a better corrosion resistant lube is sufficient.



For my carry guns, I use motorcycle chain wax, diluted with odorless mineral spirits.  This is more rub resistant than any oil and lasts at least a week, even in this current swamp butt weather we have had in Texas.