I've found that bullet runout has more effect on accuracy than whether the brass is new or once fired. However, all of my rifles have min spec chambers and minimum headspace so new brass isn't going to expand as much as in a factory rifle. My bull this year was also taken with handloads in new unfired brass. In my case it was Norma brass that I'd prepped and neck turned, but the cases I took hunting were unfired. I had 28 unfired cases left from the original 100, I'd used the others over the years for hunting and load workup and they were getting a little long in the tooth. After working up loads in the older cases I pulled out the new cases and loaded them for the hunt. I spun the loaded ammo on a concentricity gauge and used the straightest ones for hunting, I marked those over .003" runout as sighters. The 145 Barnes LRX worked on my bull at 380 yds.
For my prairie dog rifles I use the cheapest decent brass available and make it straight. The last 22-250 I had built I bought 500 pieces of Prvi brass then sorted, trimmed, neck turned, uniformed the primer pockets, deburred the flash hole and annealed. It's now as good as anything out there and shoots great. I likely wouldn't have had to do that with Lapua brass but it just took a little time and I enjoy the hobby, and I saved some money.
