The lethality of a bullet depends on the energy required to penetrate or destroy its target. Whether it's a headshot at 540 meters or hitting an enemy behind cover like a glass windshield, door, or cinder-block wall, the bullet needs sufficient energy to penetrate the obstacle and still achieve a lethal effect. The same principle applies to hunting animals. For instance, a .223 round might take down a human with a well-placed shot, but it would merely startle a wild hog if it doesn't hit a vital organ.

Choosing the right caliber is a delicate balance between recoil control, stability, and stopping power. Smaller rounds like the .223 are often considered more accurate due to minimal recoil, making them suitable for novice shooters learning to control recoil. However, when dealing with game animals larger than oneself, other factors come into play.

Calibers like .30-06, .308, and the newer 6.5 Creedmoor are all effective options for taking down large game animals. The stopping power of larger rounds comes from their penetrating power and the shock they create in surrounding organs. In contrast, smaller rounds like .22LR may not deliver enough tissue damage and penetration, depending on the muzzle velocity of the gun.

When selecting ammunition for hunting, the type of bullet becomes crucial. For thin-skinned fur-bearing animals, rapidly-expanding hollow points and ballistic tips are suitable. However, for thick-skinned creatures like bears, hogs, or deer, soft point rounds or purpose-made hunting ammunition are preferred. Bullet expansion plays a significant role in determining the round's effectiveness for hunting.

Let's look at some examples of recommended ammunition for specific animals:

- Squirrel, Possum, and Raccoon: For these small animals, 12-gauge shotguns loaded with #6 birdshot or high-velocity .22lr are effective choices, especially for younger shooters.

- Turkey: It is generally a bad idea to hunt turkeys with a rifle, unless you’re absolutely sure you can pull off a head shot. For those who want a guaranteed kill, there are a wide variety of 12ga loads specifically designed for turkey hunting. However, the “perfect turkey load” is a point of contention. There are hunters who can argue all day about the benefits of the smaller #9 while others espouse the benefits of the #4. There are also some oddballs who use slugs, although this is not recommended. Ultimately, a good shotgun round for turkey hunting should be both dense and hard-hitting like tungsten, making it effective against the tiny target which is the bird’s head.

- Coyote: Like turkeys, there is no one-size-fits-all coyote cartridge. However, most hunters tend to stay away from large caliber rounds like .308 and 6.5 Creedmoor in favor of smaller, faster ammo such as .17 Hornet or high velocity .223. Some are even confident enough to hunt with .22lr, but the general consensus for centerfire rounds tends to hover around ammo within the 35 to 80 grain range.

Of course, a coyote can be killed with any round, but many times, the concern of a coyote hunter is not just to kill the animal, but to preserve his kill’s fur to either sell or turn into a nice ornamental piece like a trophy or rug. Purpose-built hunting ammo like the Hornady V-Max and ELDX are crowd favorites thanks to their explosive expansion and long range capabilities, respectively.

- Deer: Caliber matters, but the type of round used is equally important. Repeater rounds like 30/30 and .45-70 Government are good for medium-range engagements, while full-power cartridges like .270 to .308 and .30-06 are suitable for slightly longer ranges. Soft point ammunition or purpose-made hunting rounds like Triple Shock or Accubonds work well.

- Hogs: The thick hide of wild hogs calls for large and powerful ammunition that doesn't expand quickly. Popular rounds like soft point .308, 6.5 Creedmoor, and .338 Win Mag are effective, but larger calibers may also be used when taking down multiple hogs is the goal.

Choosing the right caliber and type of ammunition is vital when hunting different game animals. It's essential to consider the animal's size, hide thickness, and desired outcome to ensure ethical and successful hunting results.