The Right Bullet for the Job
Have you ever heard of the phrase, "using too much gun"? Probably not. Americans -rightly so- think bigger is better for everything. There's nothing wrong with a bigger TV or a bigger truck, but when it comes to using your rifle to take an animal, sometimes bigger isn't always better.
My first experience with another hunter on public land in North Carolina was a guy who just shot his first deer of the season. For those that aren't from the coastal south, the size of deer here ranges from 70-100lbs. I drove up on him dragging a deer up into his truck and decided I'd help the old guy out, as he looked pretty winded. When I reached out to grab the deer, I noticed both front legs were completely shattered. As we threw it in the bed, I asked him what he shot it with. He said, "a .300WM" . He shot this poor deer standing broadside with a 200gr bullet, directly into both shoulders. I say poor deer, but she didn't suffer one bit. Unfortunately, the loss of meat was catastrophic. I'm not sure if he could even recover any off the front half without bone and/or bullet fragments.
Personally, I think he was using too much gun, something I see a lot of first timers and even seasoned hunters do. Sure, that gun and bullet combo will kill just about anything in North America, but if you hunt smaller animals, you're losing a bit of flexibility. Not to mention they do a number on your shoulder. Here in North Carolina, you can be completely fine with a smaller caliber round, just as long as it has a good bullet. But what makes a bullet "good"? First, you need to ask yourself what you're shooting and how far you can reasonably assume to make a shot. You want it to be accurate so you can actually hit what you're aiming at as well as have enough energy to penetrate what you're aiming at. Two things I wish I knew when I was starting out trying to find good hunting bullets are ballistic coefficient (BC) and sectional density (SD). SD is the ratio between a bullet's weight and its cross-sectional area; the BC is how well the bullet slips through the air.
If you plan on being able to shoot at a distance of more than 300yards, you should really care about the BC. The number is expressed as a decimal to the nearest thousandth with no unit. When you look at manufactures' bullet offerings, you'll see both G1 and G7, with the former being a higher number. For most hunting purposes, you should completely forget about G1. It's an old way of measuring, meant for flat based bullets (if you're using flat based bullets, you really shouldn't care about the BC). G7 is a much more accurate representation for bullets with a boat tail or taper at the end, and the measurement remains constant over all speeds. Note that a high BC won't kill anything more effectively, it just will fly better. A G7 BC of .175 is ok. A G7 BC of .225 is good. A G7 BC of .275 is great. Anything over a G7 BC of .325 and you're in ultra-high territory. Not many bullets can achieve a BC this high unless they're really long and heavy.
Now let's talk about SD. It's similar to BC as it's also expressed as a decimal to the nearest thousandth with no unit. The higher the SD, the bigger game you can shoot. The number remains constant, which really evens the playing field when your comparing different weight bullets, especially of different calibers. I like to keep the same measurements as BC for simplicity's sake. A SD of .175 would be acceptable for hunting varmints and smaller game. A SD of .225 would be good for hunting larger game such as deer or pigs. A SD of .275 will be sufficient for elk, caribou, moose, and the like. Anything over an SD of .325 and you can shoot any animal on the planet.
Now that you have an idea of what those two factors are, ask yourself again what you're shooting and how far you can reasonably assume to make a shot. Please note that this information isn't every piece of the pie; there are a ton of other factors contributing to a good bullet, including, but not limited to: powder charge, speed, construction, weight, and your rifle's twist. What I hope is that you can use this article to aid your fundamental knowledge of BC and SD. I promise it will make doing your own research on bullets that fit your application easier. Of course, there's nothing wrong with going out and buying off the shelf ammo. Realistically, it's much less of a hassle, but no full spectrum hunter likes to admit they bought their ammo already loaded.
Good luck and happy hunting!