I have no experience with the 243 as a varmint round. I have used it to take deer and feral hogs. My bullet of choice is the 100 gr. Nosler Partition. I got good accuracy out of the Federal Premium loading in a Winchester model 70 Featherweight. Once I began reloading I chose the Partition again and resumed good accuracy once I found the right combo. This bullet performed well for me on deer ranging from 60-145 lbs field dressed. I also took many feral hogs ranging from about 30-350 lbs with the same load.