Lets look at the 243, 270, and 30-06


BC Velocity Energy
243/100gr .373 2960 1945

270/140gr .360 2925 2659

30-06/150 .331 2910 2820


This is the ballistics using Remington Premier Core-Lokt Ultra bullets.

Now, Lets look at figures that tell a better picture on bullet performance. Momentum value, and the Taylor Knock out value.

Momentum Value

MV= (bullet weight in grains/100) X (velocity/100)

Taylor Knock out value

TKO=(caliber X bullet weight X velocity) / 7000

So using those formulas, this is what you get

MV TKO
243 29.6 10.27
270 40.95 16.20
30-06 43.65 19.21


So, as you can see, the 243 is not the best choice for deer. Does it work, yes. Are their better choices, absolutely. Good luck