The difference in aim and impact points between a cold and hot bore may be enough for a clean miss, or it may be enough to take the animal humanely with a minimum of suffering. Typically, big game hunters and many kinds of small game hunters will want to prepare for cold-bore zero. Certain kinds of hunters who will see relatively intense and frequent shooting, however — for example, prairie dogs hunters — may want to perfect their hot-bore zero. Adjust your zero to your kind of hunting.
The Right Tool for the Job
Another consideration for hunters is the selection of the right caliber and cartridge for the species they seek and the style of hunting they will pursue. Most small game in North America (rabbits, squirrels, etc.) are taken with rimfire rifles or shotguns, using small bullets at comparatively low velocities and energy levels to preserve the meat of these small, thin-skinned animals. Legally, there may be no legal restriction on using a 7mm Remington Magnum to harvest a ground squirrel, but you’d be lucky to find anything beyond a pink mist and floating puffs of fur. My recommendation is to talk to experienced hunters or guides in your area to see what they suggest about the kind of hunting you want to do, including not just species, but also terrain. A scoped 270 bolt-action rifle may be great for eastern deer hunted in soybean fields, but a quick-handling lever action .30/30 is a better choice for deer or hogs in dense brush, and neither are great choices for Alaskan big game that may look upon you as a tasty snack. Likewise, waterfowl and game bird hunting (with the exceptions of turkeys in some states) are a shotgun-only affair, sometimes with considerable and bewildering selections of shotgun chokes, shell lengths, shot sizes, and shot materials depending on the species you desire to chase.
Know Your Limitations
Almost any modern firearm that is reasonably well-maintained and firing quality factory-made ammunition is going to be capable of more mechanical accuracy than its human operator is likely to be able to wring out of it. If you are the kind of hunter that isn’t able to make it to the range frequently to keep your shooting skills sharp, they will fall away from you. You should limit yourself to shots within your “envelope of competency,” for lack of a better term. This will vary wildly from shooter to shooter. For individual shooters, it will vary between individual weapons.