I just got home with a new Winchester Select O/U from Cabela's to find a few hairline areas where the barrels meet, but hidded by the forarm, where the blueing didn't take. If the store was around the corner and I hadn't been delayed on the purchase (already made two trips) I'd just take it back. My question is, is this anything to worry about as far as rust goes? Would applying a blueing touchup be of any help? What would you do? Like I said, when the gun is assembled, the hairlines are not visible. The sum of the few hairlines is maybe an inch total. Thanks.

I suspect it's not blued as it's a solder joint and you're seeing a solder line....I wouldn't worry about it if it was mine.

Ditto, just a solder line. Silver solder does not blue.