08-24-2013, 02:13 AM
noone Wrote:In your first picture of the inside of the upper receiver/barrel extension, there is something at about 4 o'clock relative to the barrel extension. Is that dirt, a crack, manufacturing flaw, or just an unknown bit of junk in the receiver?
If it is a crack, I would wonder if it contributes to any of the phenomenon you describe.
not sure what you are talking about but it appears to either be a fiber or a shadow depending what I think you are referencing....