Your chamber may be over sized, or the sizeing die alittle tight. If your going to load alot of ammo for it I would recomand the Dillon dies, especially if you will be loading cast bullets. They cost more but they are worth every penny. If you`ll not be loading alot at least get a carbide sizer. With the carbide sizer you do not need to lube your cases and they are better than the old steel sizeing dies do any way.