Unless they've changed their brass, I would anneal it. Starline brass is very well made as far as dimensions go, but I don't know if it's their formula or what but they're large case brass is very stiff in my estimation. I'm loading the 45-90 right now for the Big Hill shoot in 2 weeks and I have to anneal every two firings. I still don't like the way the bullet seats in the case. It's not very uniform. I have never annealed my Winchester 45-70 brass and I fired it at least 10 times if not more. The bullets seat the same from the first firing to the last and I wish Starline would behave the same way. Other people may have just the opposite take I do.