With decent bullets, the product of energy and sectional density will give a good idea of penetrating destructiveness.
Bill St.Clair's muzzle energy computer is here:
http://billstclair.com/energy.htmlPlug in your bullet weight, down range velocity, and bullet caliber and you will get the computations.
For example, a 45ACP with 230gr @800fps(muzzle) gives an E*SD of 53, and is not something you would want to shoot an elk with.
A 150gr 30/30 with a velocity of 1700fps(200yds) gives an E*SD =229, which would be about the absolute minimum,IMO, for sport hunting of elk. But the biggest you can shoot accurately is best.
A 300gr .375H&H downrange 200yds with velocity slowed to 2200 has an E*SD of 983!
A 270 gr .375 at 500yds with velocity of 1933fps still has an E*SD over 600.