That reminds me of one of the things I like best about the 310 arrangement... since they only neck size, it is frequently possible to do a "work around" for calibers Lyman never intended. My current personal favorite is the Maynard 1873 cartridge in 40-40 that I am loading using the current-production 40-65 dies. Couldn't be better if they meant to do it that way!
Froggie