I hunted with one for about 20 years. Worked great on young deer. usually dropped them on the spot. The last buck I killed with it was a big old one and it took a whole magazine to make him lie down. Never took it hunting again.
The year before one of my bucks took 3 shots and 1/4 mile of running to go down. I switched to a bigger rifle and don't have those problems anymore. That's my experience with the 243. I figure it would make a really good coyote rifle.