I am considering a JES rebore to 45-60 win. I will cut the chamber with a 4D reamer and use correct HS Starline brass. Now the 64K question, what boolit diameter? Published info runs from 0.406" to 0.411 boolit OD. I can spec the groove to be a couple thousands under boolit size so what do you folks think? I will be loading to a max OAL of 2.6", using a 260g boolit.
BB