I agree it's somewhat of a gamble, but it is an easily underestimated round. There's a ton of murders with .22LR every year.

The brain is more resilient than people realize:

http://news.bbc.co.uk/1/hi/health/3685791.stm

(I couldn't find a picture of the guy who shot 12 nails into his head deliberately, but he survived http://seattletimes.nwsource.com/html/localnews/2002945554_w...)

Suicide is a bad enough idea by itself, but the possibility of turning into James Brady is very high when not doing it right. I mean, if you're dead, why spare expense? Get a 45 ACP minimum.

Perhaps in Australia it's easier to get a .22LR "target pistol" than larger calibers.