Sambo,
I agree with the assessment that the bolt would need to be pulled to eject a loaded round. Not sure why he is looking to buy one of these. I do not see any advantage to do a 338 RUM on a short action. Maybe someone could enlighten me.
Correct me if I am wrong but as far as I know the 40X action is a solid bottom version of the 700 available only from the Custom Shop. A short action 338 RUM would work okay but loaded rounds would not be able to be ejected without removing the bolt. Empties might eject okay. If it were me I would spend the same money having a good gunsmith build a 338 RUM on a custom or blueprinted long action and probably have a better rifle. Just my two cents.