Unless you disclose, at 2.5 times the size of Texas, the State of Alaska would almost never be aware unless you're in a public campground. But if you tell them as you should by law, you have to submit a Defense of Life or Property Report Form as well as turning over the bear's hide and skull. Alaskans can take grizzlies with the proper license, tag, season, and areas. Non-Alaskans need a registered guide in most cases.
I've never shot a bear with a 10mm. The bear in the pic was harvested with a rifle in a remote area and reported to the State in accordance with hunting laws. I wouldn't want to try a 10mm in a bear defense situation as the caliber is lacking for that purpose. And that was my only point. 10mm Heavy Buffalo Bore is 607 ft. lbs. at the muzzle (Item 21DG 190/20), the Buffalo Bore Heavy 460 I use is 2,455 ft. lbs., or slightly over 400% of the 10mm's kinetic energy. Shot placement is not really going to be possible w/a charging grizzly. 10mm and 460 pictured.
The 500 is not a "far better" choice. While the 500 generates more kinetic energy than the .460 at all ranges, the two are close enough in knock-down power for bear defense at close range it is not a factor. As you say at 2,000 ft. lbs., that is "more than enough to cancel a bear's ticket."
What does matter is the 460 has significantly less recoil, some reviews say 33% less (e.g. Chuck Hawks). With high powered loads, the .460 kicks over three times as hard as a full power .44 Magnum and the .500 kicks over four times are hard as a .44 Magnum. My own Buffalo Bore Heavy factory load is 300 grain with roughly 2,300 ft. lbs. at the barrel in a 3.5" barrel and 2,455 ft. lbs in the longer test barrel. It is punishing but accurate to shoot. I practice DA at 15 yards and SA at 25. Sore wrist a couple times.
If you can handle a big-bore revolver with heavy loads, they do offer profoundly more on-impact authority over any other handgun. If you can’t, opt for increased accuracy and rapid-fire capability with a 10mm alternative.
And lastly, a firearm is my second line of defense. Bear spray is more effective, according to a study of 83 encounters from 1985 and 2006 that was published in the Journal of Wildlife Management. “Of all persons carrying sprays, 98% were uninjured by bears in close-range encounters,” the review states.
A study of 269 incidents involving firearms and bears in Alaska between 1883 and 2009 showed that bears were killed in 61 percent of the incidents. “Although firearms have failed to protect some users, they are the only deterrent that can lethally stop an aggressive bear, reads the article “Efficacy of Firearms for Bear Deterrence in Alaska” that the Journal of Wildlife Management also published.
The U.S. Fish and Wildlife Service compared the two methods of defense in a paper “Bear Spray vs. Bullets. Which offers better protection?”. “Based on [USFWS law enforcement] investigations of human-bear encounters since 1992, persons encountering grizzlies and defending themselves with firearms suffer injury about 50 [percent] of the time,” the report reads. “During the same period, persons defending themselves with pepper spray escaped injury most of the time, and those that were injured experienced shorter duration attacks and less severe injuries.”
Did you see the news on the large pile of bear scat found outside Anchorage? It contained gold teeth, a 10mm Glock, and an empty magazine in it. No need to call BS. It's tongue-in-cheek to make a point.
