with 22.cal? my mom is getting a keltec plr-22 for home defense an she is getting a ar-16 clip which is 30 rounds of 22.cal long rifle hollow points i personally think that is a overkill

Short answer... Only if they're on PCP and she's a crappy shot. I seriously doubt that a "normal" person will continue advancing after being shot, just once. That part of the brain that says, "Hey! Stop being a dumba**", usually kicks in after being shot once! On a side note, I've owned the Keltec P-11 and I'd recommend your mom get that, instead. It's a 9mm parabellum and she can load it with defense (hollow point) rounds, which gives it a nice wound width with acceptable accuracy at close range. I've had lots of experience shooting guns, so I'm pretty decent at it, and I kept a four-inch spread at thirty feet with hollow points, which isn't too bad. As a bonus, it's extremely compact and was (not sure if it still is) the smallest and lightest 9mm when it first came out. It looks almost like 007's PPK... Which is a bonus on my nerd-o-meter!!! Good luck!

That's definitely overkill. Your mom should go to the range and practice on shooting center mass, at varying distances. 3-4 shots from a .22 caliber is quite enough to deter any attacker. She should also try to upgrade to a higher caliber. If she is afraid of too much kick then a .38 caliber revolver loaded with HP or semi-wad cutter rounds is an excellent home defense pistol, 1-2 shots from one of these puppies will not only deter an attacker but will pretty much stop him from making any other house calls. Permanently.