I have to throw my 2 cents worth in. I use the K31 dies made by CH4D, they also make a regular 7.5 Swiss die that gets you closer to unfired size. I also have a very old 7.5 Swiss die made by CH when they were still in CA. I agree with Parashooter, if you make use of the cone by properly sizing. The effort for the old die wasn't a big deal, I have RCBS's largest press. Elongation was a concern, I've read a post on castboolits where a fellow had trouble after his first Lee die full length sizing with OAL of the case. But it was PRVI brass, maybe he just got a slightly overlength lot. I wonder Parashooter, for a time the brass that makes up that cone is semi-plastic, and I know there are lot of K31owners shooting loads that don't even seal the case. How even is the flow of gases and byproducts that force there way through that cone. Wouldn't it contribute to accuracy to have the case wall nearer to the support of the chamber at the beginning of this? I'm going to keep using my CH4D K31 die, the shoulder on a fully sized case mics .469, and I'll just be happy with what I got, as everyone should be with what works for them. I think that slightly fatter shoulder saves me some lead shaving when feeding cast bullets from the magazine, now that contributes to accuracy!