I was replacing a trigger in one of my AR’s and went to take a picture of it. I couldn’t get the lighting right and so I used a flash. When I went back and looked at the photos, I noticed that the one without the flash looks jet black (same as it does in person). However, under intensely bright light, specs of light red start to show up on the trigger. See the photos below:
Now, keep in mind this is pretty much a new trigger. I got curious and looked at my fixed FSB AR’s and noticed the same thing. Jet black on person/under normal light, some reddish colors under a camera flash. Same thing on the BCG’s. My stainless guns and blues finishes don’t show any of this.
So… is this rust (meaning, lack of proper rust protection)? Or simply normal for parkerizing? When scrubbed, the cleaning patches I use come back clean. I keep my AR’s typically slathered in oil/CLP, and they’re stored in gun socks, so I doubt it’s corrosion after the fact.
Are your bolt stop and mag release gold plated? It’s just the color of the filament in your flash reflecting off of the shiny parts. Shoot the flash through a piece of white paper and it will probably go away.
If the red flecks are showing up on your receiver, it’s not rust. Aluminum corrodes but does not rust. Aluminum surface corrosion usually shows up as white powder. Sometimes, if the corrosion runs deeper or is caused fretting, it’ll be dark grey
Might just be the lighting, or it might be a little bit of oxidation. The trigger is constantly exposed to the salt and oils in your skin, so it wouldn’t surprise me. If you can’t see it with the naked eye in bright light, then it probably isn’t really there. To find out one way or the other, put a very light coat of Hoppe’s on a patch, then rub the trigger for a few minutes. If the patch turns a reddish brown, then it’s probably rust.
This brings to mind an article from a few years back about the Star Model B (article found here) where it talks about a “mucky purple color” in regards to the finish. However, it is just that - the finish. If running a wet (from whatever solution) patch over it didn’t bring up anything (like you said they didn’t in post #3), I’d say it was a negligible anomaly in the finishing step of the manufacturing process. Looks odd, but barring anything I can think of, it shouldn’t be an issue.
Actually, if anything, it looks like a copper deposit similar to what some rougher feed ramps show after a day of shooting, but that hypothesis doesn’t make sense here.
I have similar “patina” on all three of my AR FSB. They came straight from BCM that way and it is also only visible under strong light.
using the gun will create “off colors” as was mentioned due to the moisture/salts in our skin or they can be created during the parkerizing process either intentional or not. when the parts come out of the parkerizing tank they are completely unprotected due to the abscence of oil and flash rust can happening almost instantaniously. The first time i parked an AK reciever i actually let the part sit for a few minutes before dousing it with oil to generate a black/brown patina to match the “worn” look of the parts kit i was using.
As long as there isnt any rust coming off on a patch i would just chalk it up to character of a gun that is actually being used, IMO.
Slight patina on the metal. Normal. If it’s chapping your hide, cold blue it. Better yet, perhaps paint it. Wear and tear on a rifle makes it look better anyways.
BTW, take a look at your bolt hold open and mag catch in both pics. First pic, nice n dark. Second pic all yellowish and completely opposite color of your lower receiver. Faulty parts there too? Not likely my friend. Merely different metals responding differently to finishes, environment and use. Just don’t use the flash when you wanna showcase your guns. LOL!!!