Just completed my experiment using a Redding type S fl die to form perfect 338 whisper brass.
Those of us who've been wanting to try 338W but couldnt find dies from SSK or couldnt wait for CH4D....... Problem solved!
Seater die also tested and both function perfectly.
Now to get a reamer ground that fits 338W into an AR-15 mag....
..and talk to AR Performance about some .473 bolts and extensions. This is going to make some feral hogs very unhappy.