USHL is different than USH. The L is for light and can be mounted to a sb1 frame as I understand it.
Thats what they told me and that is why I am confused. I spoke with several customer service reps over the months and they continually stated it was a proper match. Its not in the barrel program but they gave me the part number for the work order.
I am not complaining about the barrel, it looks nice and the scope mount is welded to the barrel not short screwed. I was after a light weight 12 but was expecting the new twist configuration. I am building my own stock and fore arm to make up the weight and feel I want.