Yes, yes, and by all means yes. Shouldn't even be a question. I go through thousands and thousands of new Starline 357 brass every year. 4K this month alone. There is about a 20% occurence of out of round due to shipping. It is also slightly over sized, and the case tension is on the lighter side. Resizing will make each piece consistent. You can validate this by doing some unsized and sized strings of new brass....I consistently see about a 10% improvement of SD across the board on every caliber I load sizing new brass.