RE: opening up dies
Big Country, grinding the bottom of the die is not necessary, RCBS etc., use this method to make custom dies for custom chambers, I short chamber rifles, load for them then go to the range and determine if I want to finish the chamber or use another barrel, all with one set of dies, the purpose for grinding the top off was for sizing a case for a chamber that does not exist in 338, to have a die made in that configuration would cost more than I have in the rifle and to ream a die blank ($28.00)would mean reducing the the neck portion of the reamer, at $100.00 plus to replace a chamber reamer, I had rather dedicate a sizing die for that purpose. I know I could reducethe diameter of the chamber reamer and still ream a chamber if I acquire a reamer for cutting the neck in the chamber.
I size cases with one set of dies from-.016 below a go-gage to infinity.
Grinding the top of a shell holder is not necessary but it is done, Redding competition shell holders are not necessary but if you have them, use them.
F. Guffey