ORIGINAL: zrexpilot

Id pick the .243 over both. Clearly a superior varmint cartridge. handloaded with a 55 gr bullet you can acheive over 4000 fps easy. retains more velocity and energy out to 500 yds with less wind drift also, but I would opt for a little less velocity and go with the .243 in federals 85 gr. Not to much difference in trajectory but a lot less wind drift and a lot more retained energy.
Just do a comparo.
heres one from winchesters site.
http://www.winchester.com/products/catalog/comparerifle.aspx?symbol=SBST22250A&atype=1&am p;ctype=1&action=1