I have gone completely through a Yildiz O/U to the point of a complete tear down and reassembly. Other than using pins where a more expensive gun would use a threaded part, they are built quite well. They use an aluminum receiver and the would it metal fit isn't as tight as say a Franchi, Beretta or Citori, but internally they are just as well built, and a fraction of the cost f those three. Of those three, the Franchi Instinct SL also uses an aluminum receiver.