Just bought Lee 3 die set and trying to fl size for my bolt action rifle. I have two types of once fired brass, and they were fired in two different rifles which are not the one I'm loading for. Anyway after full length sizing, one batch of brass chambers fine but the doesn't . The Lee fl die doesn't seem to be setting the shoulder correctly. So what do I do? I ground a shell holder to go deeper and didn't help with chambering