I think Y'all are saying that you can't just simply buy a FL die that fits any reamer but rather buy the reamer and have a die made to fit the reamer...is that what your saying? Make that question fit those that have the stuff to create their own dies.
Please believe that I don't know what's going on these days. When I quit traveling, almost everybody was using a bump die and those that were using FL dies weren't doing well. Also believe that I know full well the problems of just bumping but found an "acorn" now and then that satisfied my needs.
Kinda mirrors my experience with sizing dies.
I first took the plunge in 1999. Bought a used Benchrest rifle(Stolle Panda 6PPC) from a well known veteran shooter. The rifle came with an unmodified Wilson neck die and seater,An arbor press and a plastic mallet. The seller turned some brass for me and showed me how to use the Wilson neck die and seater. I used that brass in competition for a whole year, because I didn't trust my neck turning skills. Started out with 20 pieces of neck turned brass. By the end of the year,only seven pieces were still usable. I looked around at some of the matches and noticed that a good number of shooters were using the same set up as mine. A few were using full length dies. I'd be willing to bet that a reputable number of aggregates have been won by shooters using Wilson Neck Dies. I won a few myself. I have Never owned a bump die. My mentor never mentioned such an item.
I switched to full length sizing dies when somebody promised me that I could shoot smaller aggs using hot loads of V-133.
Glenn