Quite some time ago I bought a batch of winchester .308 win brass. I have full length resized it every time I have reloaded it. I clean the primer pockets and trim to length and debur the mouths every time. I know I have not kept track of which brass has been used what number of times but I would swear that some of the ones I am having problems with have only been used 5 or 6 times. The problem I am having is web thinning. I have been told that each time the brass is FL resized the brass will flow toward the mouth of the case and that if ignored this will (obviously) lead to case head separation. Questions: 1. Should this be happening after only 5 or 6 FL resizings? 2. Would this be a sign of too much case pressure from my loads as well as sizing? (I'm not seeing any other signs of being over a safe load pressure.) 3. Is this something common to the brand of brass or would this be happening to any brand because of my FL sizing. I specifically bought win brass because I heard rem brass is too brittle. After all that, do you have reccomendations on how to reduce this problem? I am thinking of buying a batch of Lapua brass and a lee collet neck die. Any comments on this would also be appreciated. Thanks all.