Anyone have any experience with these calibers? I realize that they are hard on barrels due to the extreme velocity. They make some nice looking rifles with some very nice price tags. Would it be worth it to build a custom rifle based on one of their calibers? Whether it be one of their short mags or long? How do the short mags compare to the WSM's and the long to say the 300Winmag and the .300 WBY?