I can assure you that not all shotgun barrels are made in Turkey - especially on some of the better guns.
Everybody has a budget / and I didn't mean to come off saying that spending more is the only way to buy a decent shotgun. But there is a big gap between the "Turkish" made guns and Miroku, that I think still makes many of the barrels for Browning, as an example ( and yes, its a big price jump as well ). I think many people would tell you its also a big jump in quality - and companies like Miroku have been tested over time. A new factory in Turkey, who knows what they can do ...
There are a lot of guns being made in Turkey these days - and honestly I can't keep track of them all ( or which corporations owns who these days in the gun industry ..), its confusing.
I don't know anything about S&W's warranty - but just playing devils advocate with you - where do you have to ship the gun to get the warranty work done, how long, who pays shipping, etc. If it takes 3 - 6 months to get a gun back, I'll be less than impressed. If you need a replacement firing pin, a spring, or another minor part, can you get them / who has them in the US ?
If you are an experienced shotgunner - own several shotguns - maybe its ok to take a risk on one of these S&W's - try it out / if you don't like it sell it. But if this is going to be a primary gun - I'm suggesting you look over the used market for a Beretta, Browning, Remington and Benelli - and see if there is something out there you like just as well - maybe for less money than the S&W. In my experience, I will tell you hands down - a used Beretta, Browning or Benelli will command a much higher price in the used market - 10 years from now than any gun made in Turkey I've seen in the last 4 or 5 years. They may get better - but right now - based on the guns I've see they don't look very good. But like I said - I have not seen any of the S&W shotguns / let alone take one apart to take a look inside / so all I can say is buyer beware at this point.