brass shavings on firing pin-AR

[rmuller]

I have two new rifles from the factory, not something i put together from parts, both of them are piston guns.

When cleaning i noticed that the firing pin is covered is little shavings of what appears to be brass. I can actually remove the firing pin and bolt and blow brass powder out of the cavity inside. I thought this might be because both guns are new, but one of them is now at around 1K rounds and still has the same issue. "if it even is an issue". I have never seen this before so i'm curious of the possible causes and what this might affect. The pieces are not all circular like it is a firing pin hole out of tolerance, they are small shavings..almost dust.

To date neither gun has had a hiccup of any kind.

 

[Wormydog1724]

The extractor is removing or shaving brass from the casings and it's finding it's way into the bolt and on the firing pin. Normal in my book.

 

[rmuller]

there have been no problems yet, but i'm worried about some of the larger and higher round count matches and running into reliability issues as the amount of shavings build up inside the bolt.

any ideas on whether this will start to reduce as the extractor wears a little?

 

[mike cyrwus]

might be that since theres no gas coming through the bolt to blow that brass dust out,it just stays there and is normal
id pm one of those adams arms guys on fb

 

[rmuller]

that makes perfect sense...thanks! I will hit up Granger