10" behind the front leg bone, mid-height on the body, is deadly. Moving further back, the organ directly behind the diaphram is the liver, and a liver shot animal is a dead animal also. We don't have to agree, and I don't fault you for your preference. My success with this shot placement spans 40 years now, and without exception, this shot placement kills quickly and results in minimal edible meat damage.
On the other hand, game animals shot forward of the front leg bone are failed hits, unless the animal is quartering toward you. I've seen those forward of the front leg hits by others I've hunted with, hunters who targeted the front leg/shoulder and errored slightly forward with their shot placement. In fact I have finished off some of those wounded animals myself. I would rather error behind the front leg than chance a hit in front of it.
I've got 40 years of repeated success with my preferred shot placement and it sounds like you do also. If I was a guide (I am not) and uncertain of my client's prowess with a rifle, I'd probably tell them to shoot a bear to break the front shoulders also. That way if the animal headed for cover, I could know before the animal reached the alders that additional finishing shots were in order.
On the other hand, when I shoot a bear through the middle of the ribcage, if it heads for the alders I have no worries. And I still have edible front shoulder meat.
I tend to avoid taking really long shots on bears, because they can be such a bugger to recover without a solid first hit. But shooting at other large game animals at distances where terminal bullet velocity has dropped near minimum required bullet expansion velocity, I will tend to aim more for the front shoulder area in order to improve the odds of bullet expansion due to impact with front leg/shoulder bone. And at ranges past 600 yards, the bullets out of the rifles I'm using have slowed enough that bullet-caused meat damage is pretty minimal, compared to the higher velocity impacts at closer ranges.
We may be talking basically the same aiming point on bear. Earlier you mentioned 10" back of the shoulder, which to me is different than 10" back of the "shoulder bone". Also the "center of the ribs" is sort of misleading. But the "shoulder bone" on a bear hooks a bit to the front. To me "center of the ribs" constitutes a gut shot. Likewise when I talk about "centered on the shoulder" seems to be confusing to some. I'm not refering to center on the shoulder "bone." (That too is a very small target). But, if you center on the shoulder it gives you about a 10" circle of deadly shot placement on a bear.
Nevertheless, after all is said and done, the shot placement depends entirely on circumstances in the field. I have been known to direct a client to make a head shot a time or two, because that was the best (or only) choice available.
It certainly is not the optimum choice, but when you are in thick alders at short range you take what you can get. Of course circumstances also dictate the range. Closer you can get the better, but sometimes 300 or more yards is as close as you get. So many variables.
Two years ago was my last hunt on Kodiak Island. The Alaska Department of Fish and Game literature supplied with my permit packet at that time recommended lung shots because they were deadly, and they offered the most margin for aiming error. Fish and Game believes more bears than necessary are being wounded by hunters trying to break the bears down with shoulder/front leg shots, and erring too far forward in their aiming point. Slightly farther back wipes out the lungs and ensures a quickly-expired bear.
To clarify my prior posts: my aiming point is just behind the front leg muscle of the bear and mid-height on the ribcage - top to bottom wise. I understand I could move forward into the front leg muscle and bone and still get a killing shot that also has the potential to disable the bear (break the skeletal structure) by breaking bone. However I shoot just behind the leg muscle on a standing broadside positioned bear, just like one would do with a broadhead-tipped arrow (avoiding the bones), and these bears die in short order.
The majority of wounded bears that get away IMO is nervousness (buck-fever) and not taking the time to aim properly. I've had clients miss at fifty yards. I've had bears shot in the foot, the nose, the leg, the guts, you name it. If the bear cooperated with a broadside shot and I could get the hunter to hit the bear anywhere through the shoulders with any of the big magnums, that bear was in the bag. Some guys can stay calm and place their shots well and some can't. The best thing a first time bear hunter can do is do a lot of shooting with the gun they are going to use before the hunt. Get it sighted in good and get comfortable with the rifle. If you have trouble holding a big magnum, put on a muzzle break and a good recoil pad. When it comes time to make the shot, calm down.... and don't shoot him in the guts or foot.
Theodore, when you have a 10 foot bear raise up fifty feet in front of you in an alder patch with his ears pinned back and hackles up, you'll gladly take that head shot. The situation is not always perfect.
Makes me smile. I can imagine some of the clients pose as great a risk to health and safety as the brown/grizzly bears at the moment of battle. I will admit, the first big Kodiak brown bear I saw (his front track measured 8 3/4 - 9 inches wide) looked like a barn door and was surprisingly unsettling on my nerves. I had slowly and cautiously tracked the bear around in and out of some alder patches in the prior nights 1/2" fresh snow fall when he caught my scent and awoke from a deep sleep about 70 yards away. Never got a shot at the bear. At 70 yards he looked absolutely huge even behind some cover of alders. I was alone and fully aware of that fact. Just me and the bruin. I'd hunted all my life and had seen and shot any number of black bears large and small, but still wasn't prepared for the immense size of that brown bear. Now that I've shot a few and been around a number of them, I don't experience that same shock effect. The shear size alone of a big boar brown bear is a good enough reason for the uninitiated to be accompanied by a guide with prior experiences in the company of these monsters.