I sold some boxer primed 7.5 X 55 Swiss brass that was once fired in one (or more) of my K-31's. Today I received a note from the buyer indicating that the 80 percent of the brass wouldn't resize properly to work in his K-31 after resizing it in his set of Redding dies. I tried resizing several pieces of this brass from the same lot with my Redding dies and I have no problem with them working in several of my K-31's. I understand that neck sizing this brass can be problematic but I have never had any problems full length resizing this brass and having it not fit in any of my K-31's. He said the brass is extremely difficult to resize and is concerned he may damage his press or the Redding dies. I just use RCBS lube on one of the Lyman lube pads and have had no problems running it through my Redding dies with a RCBS RockChucker. Any idea what might be causing this problem? Thanks.