Case necks are going to get thicker when you downsize them. And certain brands of brass seem to have a reputation for thicker neck walls. Winchester is probably the thinnest. Depending upon how tight your chamber is cut necks could be a little on the thick side and give you a problem with proper bullet release on ignition so watch out for that. If you haven't ever played with a neck Turner now might be the time to get one.... you can true up those necks after downsizing. The reward should be better concentricity after sizing and more accuracy.... and you should only have to do it once!
