I was wondering how obvious the difference is between the old rifling and the new ultragon ? I called H&R and they told me that all of the USH barrels made this year with serial numbers that start with HY or NY are ultragon rifled. But I work in the automotive repair industry and know that production cut off dates are not always written in stone. I've seen the picture in the brochure and looked at a couple of guns last night. My eyesight's not what it used to be but I couldn't see any difference. Is it my eyes , do you need a borescope to see it or maybe theese to guns have the old style rifling?