White powder on lower receiver?

[Livefreeordie92]

So one of my friends here in OKC got an AR and he noticed a white powdery substance on the outside of the magwell on his lower. Said it wipes away with CLP but will randomly come back. Any ideas? I've searched the Internet and haven't come up with anything quite like this. I'm not going to get into brands or manufacturers because I don't think that this is anything that would require sending back nor do I believe it has anything to do with who manufactured the lower, more so te environment it's being stored in. The rifle is kept in a safe when not in use. If you look, you can also see it in the dimples in the front of the magazine.

[joeyjoe]

tell your "friend" to dunk it in a tub of slip 2000 EWL and take it out and shoot it. Ive seen white stuff on Colt grips and, occasionally, on aluminum forgings. I dunno what the stuff is, but it appears to be somewhat ubiquitous. It's really hard to tell whats what in the uploaded pic because of the flash. From that picture, seems like a non issue, but ill take your word for it that something is funky. Another pic?

[Livefreeordie92]

tell your "friend" to dunk it in a tub of slip 2000 EWL and take it out and shoot it. Ive seen white stuff on Colt grips and, occasionally, on aluminum forgings. I dunno what the stuff is, but it appears to be somewhat ubiquitous. It's really hard to tell whats what in the uploaded pic because of the flash. From that picture, seems like a non issue, but ill take your word for it that something is funky. Another pic?

I'll have to ask him to send another, it really isn't my rifle. None of mine have ever experienced this and I've had them stored in several locations.

[JasonB1]

Was it new? I have a lower I used Citristrip to remove paint from and it looks like that.

[Livefreeordie92]

Was it new? I have a lower I used Citristrip to remove paint from and it looks like that.

It's new. Rifle has maybe 150 rounds through it.

[nolt]

https://www.m4carbine.net/showthread...nd-end-of-comp

dunno if that's relevant at all with an anodized receiver but fyi, fwiw, etc.
mystery substances do occur.

[NoveskeFan]

I dont recall what brand, but I had a lower that had that. I warmed it up with a blow dryer, applied Froglubed and wiped it off. It never came back.

[Scrubber3]

The white "powder" is most likely dead skin cells or a combination of skin and soap residue. I'll bet money he's been holding the rifle right there.

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[Briman1001]

That and maybe some salt residue also?

[Livefreeordie92]

The white "powder" is most likely dead skin cells or a combination of skin and soap residue. I'll bet money he's been holding the rifle right there.

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Never thought of that... Good observation.