Foreign object in Radway 5.56 NATO casing

[squirreld]

I was out doing some shooting over the nice long weekend and after I pulled the clean rounds out of the tumbler, I heard something rattling around.
Initially, I thought it was a spent primer as some of those make their way into the case tray.
After a closer look, it was not a spent primer.
Had to cut the case in half to get it out.

http://home.earthlink.net/~squirreld/SS1091.jpg
http://home.earthlink.net/~squirreld/SS1092.jpg
http://home.earthlink.net/~squirreld/SS1093.jpg

What the heck is it and how did it get in there from the factory?

[WiskyT]

Is it metal?

[dkf]

Maybe the excess brass from the neck when it was trimmed after forming?:dunno: Is it magnetic?

[squirreld]

Non magnetic.
Looks like it is a piece of brass from the neck area during the cases birth.

I don't know how the brass cases are made.