As far as Redhawk's go, I have and love the 5-1/2" blued one (
http://www.ruger-firearms.com/Firearms/FAProdResults?function=famid&famid=6&variation=Blu ed&bct=Yes&type=Revolver ). If I was going to potentially encounter Grizzlies, I would probably get a heavier load, but I just carry the fire-breathing 1,610 fps/1,036fpe 180 gr loads. I'm pretty sure that that will stop a black bear.
As far as the .22 LR rimfire round goes, it's the worst possible choice for personal defense. Go to the Federal Cartidge Company and please show me the .22 LR load that is recommended for personal defense. There are none. They are only recomended for varmints and target shooting. There is a reason for that. Actually several.
As a matter of physics, it's the energy of a projectile that damages, disrupts, and kills. Some bullets are better constructed for a particular purpose and, thus, distribute the energy on impact in a more deadly manner. However, assuming you have an appropriate bullet type, it's the energy that disrupts the recipient of the projectile. .40 S&W or .45 ACP = upwards of 500 fpe in certain loads. The .22 = about 115 fpe.
Another relevant concept is that the likelihood of KILLING an animal is proportional to the square of the times you shoot it. Thus, if you shoot a person 5 times with a .22, you are 25 times more likely to kill him than if you merely shot him once. You are also probably more likely to kill someone by shooting him 3-5 times with a .22 than you are by shooting him once with a .40, but it will probably take a while and won't impede his ability to continue aggresive conduct nearly as much as a single shot from a .40 or .45. This is because, while the five .22s are more likely to strike a vital artery in the areas where they create a permanent cavity, the temporary cavities are much, much smaller than those created by real personal defense loads. Thus, you can shoot some aggressor five times with a .22 and he likely will ultimately bleed to death, but won't shut down immediately. Someone hit with a 500 ft-lb bullet will be much more likey to experience immediate disruption due to both the permanent and temporary cavities created by the round. He will likely shut down immediately. That's why the 155 gr .40 produces "one shot stops" of a person shot in the torso 96% of the time and a .22 produces one stop shots about 32% of the time. Even some .380 loads get up to almost 70%. The .22 does not cause enough shock to reliably stop a human-sized target. I would say this failure is even more pronounced when dealing with a person on certain amphetamines or narcotics.
Of course, there's nothing wrong with shooting a threatening individual multiple times with a .40 or a .45, which really seals the deal.
Further, firing your handgun madly like a machine gun is not the way to win a gun fight. Shooting with a decent caliber and making every shot count is the way to go. Trust me, you won't feel the recoil of a 9mm, .40, or .45 when someone is shooting back at you. Not one bit.
Even if you want to attack someone Machine Gun Kelly style, you can get a Glock 35 with a that holds 18 rounds (17+1) in .40. If you want to less recoil, get a 9mm Glock 18 with a 31-round magazine.
Using a .22 for home defense is like bow hunting Grizzlies. It's great if you want a tough challlenge. But, if you want to make your like easier, go with a real caliber.