If I was starting over I would purchase nothing but RCBS (type) trim/form dies, if the hand loader can adjust a die in the press to the shell holder with .000 clearances cases can be trimmed to within .001 thousands of each other, this technique eliminates the debate, size first then trim or trim first then size and the pilot that does not fit after sizing.
The trim/form die pays for it self when forming cases, if the hand loader can adjust a die in the press to the shell holder the distance from the head of the case to it's shoulder can be controlled, it is easier to move a shoulder back than move it forward.
Even it the hand loader does not have a 308 W chambered rifle the 308 W trim form die is one of the best investment, it can be used to form 7.7 Japanese, 7mm57, 8mm57, 257 Roberts etc. if the hand loader can adjust a die in the press to the shell holder and operate a file and hack saw.
The same can be said for the investment in a set of 35 Whelen or 338/06 dies, it is a good investment even if if the hand loader does not have a rifle chambered in either, again moving the shoulder back when sizing is easy, the difficult part is moving it forward without firing first, I am a big fan of forming first then firing.
F. Guffey