It's common to use military calibres, such as .223 Remington, .308 Winchester and .30-06 Springfield. These are calibres that have been mentioned many times in our conversation here. Those were all originally military cartridges that have been adapted for use in hunting.
What differentiates a military cartridge from a hunting cartridge is the kind of projectile that's installed. A hunting bullet is designed to expand on impact and cause a humane kill of the animal, whereas a military cartridge, in general, is designed to penetrate and go through defensive armour. It also has to conform with the Hague conventions on the use of military ammunition.