And now another four years later
So -- the #1 requirement of a firearm for self defense is to be able to acquire and hit the target reliably and accurately. 6 misses with a .44 magnum do not beat 6 hits with a .22
Many people cannot handle a powerful weapon. They are asleep and weirdly do not have their glasses on nor their hearing protection. Fire 6 rounds of 44 mag or .40 or 9mm in your bedroom, all occupants (wife, pets, attacker) will suffer permanent hearing damage.
Second requirement is penetration -- forget hollow points on a .22 (except for varmints) -- a .22 has low mass with decent speed, you can penetrate the 12 inches you need to.
I keep two weapons -- a suppressed Mark III Ruger Hunter with as powerful a load I can get. With laser. I can be half asleep, no glasses, and put 11 rounds into a half dollar anyplace in my bedroom. If that does not solve the problem then I have a G20 Glock (10 mm with 200 grain Double Tap rounds). I figure if I don't get them out of there with the Mark III I'll at least slow them down and give me time to wake up and get the Glock lined up. If I do, I will still be able to hear.
I use CCI Ultra Mags now ... but I am not sure it matters a lot ... it is not loud, and VERY accurate.
I see many men buy their wife a self defense gun (or other buying a new shooter a gun) -- usually a Lady Smith in .38 (weighs nothing and has no barrel) -- they go to the range. 1-2 shots they want to go home. I bring over my Mark III and all of a sudden the new shooter is having a blast picking off the center ring at 10+ yards (more than you need in your bedroom).
It may not be ideal to use a .22 -- it is definitely a very good way to start a new shooter, and not so bad as one of two handguns in a bedroom. Truth be told, I'd rather have my AR anyway and it is not that far away. The pistol is just good enough to fight your way to your carbine
I taught my 10 yo nieces to shoot the AR as the kick is minimal -- with a light and laser it will do the job at any distance (you will still be deaf).
So don't knock the lowly .22 -- it has it's place. I bet I can get more grains into a target faster than most people can with a 9mm ... at my age, in the dark, no glasses, sound asleep. And no -- I don't have time to get electronic hearing protection on as some suggest. My Mark III runs 115db -- I can shoot it indoors all day long with no damage (see chart). And yes, I have a DB meter and have measured it at the range which is not identical to in my bedroom -- I think it is louder.
http://modernsurvivalblog.com/security/hearing-protection-during-indoor-self-defense/
The point I am making is -- there is no right answer. For some a .22 is ideal. For others, not so much. Where you are matters. Age matters. Accuracy matters. Don't write it off -- the Mark III Hunter with a suppressor is pleasant and easy to shoot -- especially with Crimson Trace grips. And you can rapid fire it and do a lot of damage while waking up ... and getting a bigger gun be it a 10mm or an AR carbine (why get a a 9mm or .40 when you can have a 10mm?).