I've washed a lot of junk out of firearms I just bought, new or used. Lot's of metal filings, sometimes is chunks of cardboard or Styrofoam, but there's always extra grease in what I'm flushing with. Always clean any gun you buy or borrow. Besides, you never know if some jerk or punk has sabotaged it in the store. (I usually tear down the guns and clean up any sloppy machining, as well.)
Rick, I had a real accurate, cheap scope on a rifle once. All of a sudden, the accuracy went bad. I nearly went nuts trying all sorts of things to restore the accuracy of that rifle, a total waste. I forget how I finally discovered it was the scope but that was after I nearly ruined the gun. It's in the back of a shed now, gathering rust. (Needs a new stock, too.)
Be happy, but don't get so you have to rely on that scope, it can go bad any day now.