Matt,
This kind of a question is never wrong or worth taking a poke at, even with levity. Your 338 is a fine caliber and, with 225 grainer "anythings," will suffice on any bear that ever lived. That said, on any blackbear (which BTW are easy to kill, regardless of the stories that abound) always strive to hit the vitals with the first shot. Then be ready for a follow-up shot if necessary. Many times, you will not be able to follow with a second shot right away. If you hit the vitals, the bear will die. To concentrate on hitting a shoulder to break bones with the purpose to slow the bear down is ludicrous! IMHO, hunters need to concentrate on killing with the first shot: they owe it to the animal at the very least. This may include shoulder shots or not...it depends on the position of the bear as the trigger is pulled. I have taken several bears with a 338 and targeted the heart/lung area on all. I have never had a bear travel more than 20 yards under it's own power once shot. One did roll down the mountain about 150 yards once, but dropped on the spot for several minutes until gravity took over. Most were under 100 yards at the shot; one was 200 (the roller!) They ranged in size from 5 1/2' to 7' on the square. Have confidence in your outfit and shoot it enough to know it. have fun and be safe.
best,
bhtr