Hey , ... I use a .243 most of the time. I've taken mule deer & antelope at 300 plus yards. I too agree, it's range is far better than I can shoot. I use Winchester's 100 grain bullet off the shelf and they work just fine.
if you want to see my deer ... go to
http://www.thelodgeman.com
stroll to the Taxidermy section ... and towards the bottom ... you'll see some of our western trophies ... most by the .243