tc, here are some of my real life experiences of mine. they are fact:
well first watch this, http://www.youtube.com/watch?v=xEDo_PbAvJc
. the 22LR CCI 40gr velocitor are amazing. checkout the "fart" from the entrance wound. the bullet went to the ten inch mark. rotate those with some hot round nose for extra penetration and you are good to go.
my real life experiences:
please don't buy a ruger 10/22 for home defense. i have a couple and they are great .22lr rifles but the malfunction rate is way too high for sd/hd. i used them for years and years but would never want to depend on them.
i finally found a couple semi auto .22lr rifles that i can depend on. the sig 522 and the s&w 15-22. buy new ones, the first models of both rifles had bugs to work out.
i own the sig 522 and my brother in law owns the 15-22. i had 4 failure to feed in the 522 within the first 3 mags shot through it. that was using wal mart federal bulk, winchester 555, cci, remington bulk, and that mexican stuff.
and that was it. over 8,000 rounds of wal mart federal bulk later my sig 522 had 0 malfunctions. except for maybe 5 or so dud rounds. quite impressive for bulk ammo. the only problem is with the black dog mags, not the 522 its self. the spring in the mags are weak and if the insides aren't lubed it will hang up sometimes resulting in no round for the rifle to feed.
thats the main reason i recommend the s&w 15-22 over the 522. the newer 15-22s are flawless and have the mags to match. i would bet my life on it. i took brother in law's 15-22 to the shooting range. it was filthy dirty. i shot two boxes of the wal mart federal bulk(550 pack) with 0 malfunctions and only one round sounded under powered but cycled fine.
the 15-22 is super fun to shoot and easy to load the mags. everyone who owns one will become an expert with it. the 25 round mags are $15 at midway. i want a 15-22 and 20 mags. it will be one of my hd firearms as well as a truck gun. tbh if i had to shoot a threat at 25 to 50 yards i would much rather the 15-22 than a handgun or shotgun. it pattern much better.
if i remember correctly the 15-22s with a "D" in the serial number are the improved ones.
i brought my s&w 22a(.22lr pistol) gator hunting last year. first two gators where around the 7 foot range. i had to shoot them through the scull 5 to 7 times with round nose before they stopped. i then put wal mart federal bulk with hollow points in the mag. it was one shot stops from then on. through the scull, not the soft spot. i do not believe the human scull or rib cage will stop a .22lr.
i would keep a little headlight with the low red light(to see sights) with the gun or maybe night sights.
the 15-22 is the hd firearm i recommended to my grand mother, great aunt, and cousin's wife.
that is all.