Over worked necks. The brass work hardens and loses some of its springiness. Aneal the brass necks to return them to their proper consistency. I aneal everything larger than .223. .223 is kind of short and a bit difficult to do w/o special equipment. Because .223 brass is so plentiful, I consider work hardened brass in this caliber to be disposible.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball