This is post that I come across from another website. What are your thoughts on this? I am new to reloading and I bought some brand new winchester brass. I plan on setting my FL dies to neck size and barely bump back the shoulder. If I work up some loads with the factory resized cases (not fire formed to my gun) and find an accurate load, will the load or group change after reloading my fire formed brass? Or am I supposed to fire form my brass with some cheap bullets and light powder loads, then start working up loads.