I work on quite a few firearms,so when someone brings me a gun to fix,I will clean it first,then see if it will function.You want nasty,roaches,bugs of every type,rocks,bobby pins,you name it,I have seen it.
Now a few years ago,I won a S&W 627 P.C.(a 8 shot 357)brand new,you could not pull the trigger in double action mode.When I got it home,and took it apart,it was full of fine glass from where they glass beaded it?????It shoots fine now,but you figure for a $1200 pistol,they would atleast clean it,or even take it apart to do the touch up before it left the factory