Except when I forgot to tighten the stock screws down once! DUH! It has not shot a three round group over 1" with the limited amount of loads I have worked with. Most are .75 or better. The best has been with 168g Berger VLD's with 63.5g of Reloader 17, Remington Brass and Federal 215 primers with an OAL=3.785 (Too long to fit in the magazine but I was after accuracy so I seated on the lands). Two three shot groups back-to-back with that load were less than a half inch. When Sierra tested the rifle in Edition V they noted the consistency of accuracy with the powders they tested. Just be sure and use Federal 215 Magnum primers with the 7MM STW.
If you reload, then the STW is awsome. If you don't reload, then I would probably go with a 7MM Magnum.