I'm also a big fan of the .270; but will be the first to admit that not all .270 bullets are the same. Some will whistle right through game on broadside rib shots and not kill very quickly. Others are a little too explosive foranything but broadside rib shots. Good deer bullets often tend to be too soft for elk. And the .243 is the same deal - except even a little more touchy, since the bullet weight is about 35% less at the same velocity.

Actually, the delimna with using the .243 on deer is almost the same as the issueof using the .270 on elk: bullets that kill well on broadside rib shots tend to be too soft for the shoulder, and bullets that will stay together going through the shoulder tend to punch right through on rib shots and not kill real quickly. They each will work on the respective game animal, but they are also each at the light end of the "adequate" horsepower spectrum.