I just bought 2 sets of 308 dies and 300 brass cases. The die sets were used and the brass was supposed to be once fired. The dies are RCBS and Pacific. The problem is they don't size the cases to where they slide into the chamber easily. I use a Savage 99c with removable mags. Store bought ammo works real nice but the reloaded stuff will not go into the chamber easily. It seems to me that the brass is too big right at the base of the cartridge. Any ideas what I can do to correct the problem. I don't know if a good cleaning of the dies will help and I'm not sure what to use to clean them.