I have NiFe 48 from here: https://www.zivipf.com/epages/63862298.sf/en_GB/?ObjectPath=/Shops/63862298/Products/NiFe48-0.50/SubProducts/NF48-0.50-10m They list TCR as 400, also it's 52% Ni but they call it "48". Crazy wire has both 48 and 52, I'm "interested" with your results.