Lower Receiver Question - Pivot Pin

[bfro5482]

So I’m doing my first build and was inspecting the lower receiver. I noticed a orange sand like material in and around the pivot pin channel. It cleaned up with a cleaning cloth. I cleaned inside the channel further with a toothpick and there was more orange and black debris in the channel. There are some very minor finish issues around the channel hole.

I contacted the manufacturer and they said the orangish debris is most likely sand blasting media that got caught in the channel, and the black is likely from the anodizing process. Their explanation makes sense.

I’m not concerned it was rust or anything detrimental to the receiver because it’s aluminum.

I was just interested to hear if anyone else has had a similar experience.

Thoughts and advice are appreciated.

 

[Cemetery21]

Not uncommon to have some debris in the spring/detent hole. It's a blind hole except for the drain hole.
I just drop the spring in and then trim the spring so that the detent just starts in the hole , even if the hole is clear - makes the pivot pin easier to push out/in without that extra spring tension on the detent.

Edit: I have cleaned them out with a pipe cleaner, but I usually don't find enough debris in there to worry about. If the channel was seriously blocked, you could hand turn a drill bit to help clear it.

 

[CarJunkieLS1]

Their explanation makes perfect sense to me, and it can't be rust as lower receivers are aluminum so therefore iron oxide rust won't present itself.

 

[wiscoaster]

You could blow it out with some canned air or electronics cleaner spray.