As said, the spine shot is the only "sure" fire way to drop one in his tracks, 30, 338, 416 or what have you. A shoulder shot gurantees you nothing but maybe slowing one down momentarily. Heart and lung shot is pretty much a waste of time if his adrenaline starts up. Take a good rest, use a tough bullet, go for the spine shot when he's still. Study the animal and where his spine is from all angles so you KNOW, and aren't guessing.
Bigger calibers do have a better effect on these critters, 416 on up I'd say. Don't be surprised to have to shoot it several times with even a 338 or 375 if you don't nail the spine. A guide I know and his client had to shoot one 11 times with the 300 Ultra and 300 WM before he stayed down. My brother and my friend Bob both shot there bears 7 times, 338 WM and 375 H&H.
Prepare yourself and make every shot count, they won't be friendly after they've been hit, and they have no reservation about coming after you and very often will.
So here is my question you say hit the spine? then why not just shoot him in the neck? I think the guy you talked to maybe ment do the old trick of holding higher up on the vitals and let the bullets energy at impact break the spinel cord that is a trick some Elk hunters use. But to shoot at a 2 inch spine at 300 yards with 100cc of adrenalin running through your body I dont know to many people that can consistently hit that shot including myself.
No doubt it's a tougher shot, smaller target. I'd get closer than 300 yards if at all possible, something bigger than a 300WM don't hurt either... if you can place a shot with it. They don't let you shoot Buffalo up here with a 30 cal, just 338 and bigger... it should be the same way for Grizz IMHO. I've just heard too many stories about round after round after round needed when under guned.
A 416 is about all I truely feel comfortable with, but kids trapesin out in the woods with you hunting kind of makes a guy think how well he could stop one of them BB's if you come up on one.
When you're making your stalk, do yourself a favor and hold the rounds in the magazine down and chamber an "extra" round... keep the mag full, and plenty of extras in hand. Be prepared to single feed more one after the other if he comes at you. Stay low and aim under the chin for the spine if he does. More than likely he'll go down momentarilly from each shot, so hit him as he gets up.
Neck shot - If you ever seen one of these monsters move about much, their neck and head is always moving like no tomarrow, that would be reason for my biggest reservation. I would definitely keep on the body, not the neck FWIW. If you question your hold or accuracy one bit, I'd take the shoulder shot or get closer, or both.
Here is what gets me People always say use a 338 with a 225 grain bullet but if you look at a 300 with a 220 Partition it has more energy and more Sectional Density then a 338 even more sectional Density then a 250 grain in a 338. I think people also forget that a 300 case is bigger than a 338 case. Take my 300 for example a 200 grain Barnes TSX going 3005 fps has 4010 ft-lbs at the muzzle and at 100 yards it has 3564 ft-lbs and at 300 yards has 2794 ft-lbs with a Sectional Density of .301 how can that not be enough cause a 338 shooting a 250 grain Partition at 2700 fps has 4047 ft-lbs at the muzzle and 3508 ft-lbs at 100 yards and 2605 ft-lbs at 300 yards with a sectional density of .313 am I missing something here? I am not trying to be a smart ***** just wondering why you wouldnt want more energy at impact and why when people talk Big Bears the 30 cal is looked down on I mean if you take a 300 RUM, 30/378, or the Warbird and they have way more power than my 300 Win mag are they not big enough for bears because the bullet dia is .308? Kinda makes you wonder [img]images/icons/confused.gif[/img]
I have only had 1 experience with alaskan brown bears, but it was up close and personal. My buddy shot a brown bear at 60 yards with a 30-06 shooting partitions. I knew he hit him, but it was darn hard to tell by how fast that bear took off. This was his first time to ever kill anything and he got a little rattled on the follow-up shot. Rather than let the bear reach the brush, I thumped him in the shoulder with a .375 H & H shooting 300 grain partitions. Looked like you hit him with a truck. Bear went down hard.....but, like Brent said earlier, be ready for that bear to keep going. Bear jumped back to his feet and took off again. We both shot him again and he stayed down. Autopsy showed 2 from the 30-06 right behind the shoulder and 2 from the .375 in the shoulder. NEVER underestimate these bears ability to take a hit and keep going. After the shooting was over, we both crept up to the bear, guns at the ready, and gave him the ol poke him in the eye to see if he was dead routine. He was. We put our guns down and my buddy straddled him on his back and tried to pick up his head. His grip slipped and he sat down on the bear to get a better grip. When he did, I guess the bear's lungs had filled with air because when he sat down the bear grunted. For a split second, my buddy had a look of pure terrior in his eyes as he thought he was sitting on a wounded, but live bear. I just about broke my ribs from laughing so hard at the look on his face.
In summary, get close. Don't take a 300 yard shot. No matter what you shoot him with, expect to shoot him again and be ready to do it. You didn't say what your brother will be carrying, but I wouldn't personally buy "just" a .338 for the hunt. Depending on the back-up gun, I would either stay the course with your 300 WM or go on up to a .375.