I agree with GREYGHOSTt. Your case problem is a headspace setting problem. This is common with Encores and Contenders. We used to set up Contenders by sizing the case just enough to get the action to close. You should feel a little resistance when closing it. We now have dial indicator gauges to measure the headspace. Remember, every frame will give a different headspace reading so use the same frame/barrel combination. Once the die is properly set you should eleminate vertical group stringing and get longer case life.