I have the Redding decapping die, as well - and it works fine. I use a Forster FL size die (non-bushing) that has been custom honed to the neck diameter I need. I don't decap with that die, but it's decapping pin will also work on Lapua brass. Note that in my case, Forster had to trim a bit off the bottom of the die so that I could get a .002 setback - this apparently sometimes occurs with minimum dimension match chambers.