First time loading for 308. Got a pile of once fired Hornady Tap brass for pretty good price. Long story short. Spent over 300 rounds fighting 5 shot groups that had 3 and 2 together or 4 and a flier, cussing my chronograph, and scratching my head at random pressure signs showing up. Turns out Hornady changed their match brass at some point. I have some that weigh right at 160 gr. Some right at 172 gr. And a handful of regular head stamp Hornady at 190. All mixed together when tumbled and pulled back out in random batches. Go me.