Sell the .22-250 and buy the Chargemaster. I have shot my .22-250 once in the past two years since I got my .204R. I only haven't sold my .22-250 because the dang thing is too pretty to let someone else have it!

WYOT gave good advice on the Hornady book. Get the latest version of the book though. I think they are on the 8th edition. Also, head over to http://www.204ruger.com/forum/ to get tons of info on the .204R including a ton of reloading data.