.17HMR. It shoots flatter and it does have a fairly diverse range of bullets now with CCI coming out with 20gr hollowpoints as well as Ballistic tip. BSA also makes a scope specifically for the .17HMR bullet drop so as long as you know the distance you will always be able to hit where you aim. Not to mention it is just a lot funner than the .22mag. Heres a site about it, it has tons of charts and test and stuff.
http://www.varmintal.com/17hmr.htm