The key to getting a small caliber rifle to kill well is expansion. Obviously it is much more necessary for a .224 or .243 diameter bullet to expand than is necessary with a .30 or larger diameter bullet, assuming the bullet holds together well enough to penetrate to the vitals. Expansion is caused by speed. The faster you drive a bullet the more it will upset and expand, all things constant. For this reason in standard length barrels the 80 grain soft points, sierra 85 grain gameking bthp (my choice), or possibly a 95 grain hornady SST (a buddy started using them to hunt) might be a better choice. I have also had less than inspirational results from the 100 grain corelokts, even on deer as large (read tougher- should cause more bullet upset) as the mature axis buck I killed a couple years ago. I shot him in the lungs at 150 yards. At the shot, he trotted off with the herd and ran out of steam some 125 yards from the point of impact. Exit wound looked smaller than a quarter and there was almost no blood trail. I then switched to the federal premium loading of the sierra 85 grain BTHP, with which I have had much success (and it shot more accurately in my rifle). The load drops deer in their tracks and has enough integrity to blow though a whitetails shoulder to reach the vitals. Broadside lung shots kill with full penetration and exit wounds, and to this date with 8 deer, and a few hogs to its credit nothing has moved farther than 25 yards from the point of impact with all but two animals literally dropping in their tracks. The .243 isn't a bone crusher. Care should be taken to tuck the shot just behind the shoulder, where small bores are most effective.
