On my spine tester, a 2016 tested at 400 spine, 60#. A 2018 tested at 350 spine, 71#. From my previous experience, these shafts would ordinarily be shot from lower poundage bows than those measurements indicate. Part of that could be due to modern bows being more efficient and cut past center, thus requiring a stiffer arrow than when the spine charts were originally designed. The best test in my opinion is to shoot bare shafts until you get one that flies true, although I guess spine measurements do give you a place to start.