Looked at the 6XC, dies run 150 and up for a set. Lee dies at 30 available for the 260. I get sub .25 groups in my 204 and .5 groups with my 308 using Lees and I love the Lee collet necksizer. If the 6XC had any substantial benefit over the 260 I would go with it but I cant see enough of advantage fior the extra expense and bother of forming the cases
On the 260 AI, you can use the Lee neck sizer and I would go with it but I hate fireforming cases. An article on fireforming the 260 AI
http://www.6mmbr.com/260aiforming.html
once again is the advantage really worth the extra effort for someone of my skill level ? This is just a fun way to spend a coupel of days a week for me and I don't see myself winning any national trophies anytime in the near future. If I can place in the top 2 or 3 at my local club I would be happy, anything more would be icing on the cake.