Now that's interesting. I've been reloading Starline cases (mostly nickel) for many years. Never annealed a case and never had a problem. Most of my loads are fairly hot too.Winchester .45-70 brass is preferred by some due to it being thinner and lighter than their competition, and presumably having a greater case capacity. Starline recommends annealing their .45-70 brass each time that it's reload, IIRC, due to it being thicker and heavier than most others.
Now that's interesting. I've been reloading Starline cases (mostly nickel) for many years. Never annealed a case and never had a problem. Most of my loads are fairly hot too.