Can someone please explain what this is and how it relates to hunting??
Sorry for being ignorant!!

BC is about the same as drag coef or friction coef. The higher the number, the more aerodynamic, the lower the worse. It usually runs .15BC for big ole slugs to .5 for .308 ~180gr bullet to .7 or higher for .50 cal500gr bullet. In engineering world. Force=MassXAccel.

Then you get into vel=Vo+At. So you can figure your initial Vo. Ok, getting lost. But you know Force of air against your bullet is slowing you down. And will cause negative acceleration. BC also changes over speed.

Go to the following link and you'll find a pretty good explanation:

http://www.chuckhawks.com/bc.htm

As far as how it relates to hunting, well, let's just say that a high BC bullet is really not required unless you're shooting things way out there where bullet drop becomes a real issue. At the ranges most people shoot big game, 150 yards or less, the ballistic coefficient of the bullet really doesn't matter much at all.

Practically speaking, the ballistic coefficient of a bullet is not importantin hand gun bullets and has very little relevance to muzzleloading projectiles. It starts to make a small difference at about 250 yards - and becomes significant at ranges of around 400 yards. At 1,000 yards it is critical. If you look in some of your reloading manuals or ballistic programs, the more streamlined bullets start to make the difference between a hit and miss at some fairly long distances - further than most people should be shooting . . . .

Most hunters also want to get the maximum impact velocity out of their loads as well. How many reloaders will settle for a load that is accurate, but 150 fps below the maximum velocity for the caliber? "I might as well be shooting a 30-06" one of my companions said after determining his .300 Win Mag shot mostif its best groups with starting loads. However, a Nosler Accubond might have 150 fps more impact velocity than a Swift A-Frame at 400 yards, even though both bullets of the same weight were launched at the same muzzle velocity -due to the higher ballistic coefficient.

Anyway, the big picture is that is generally a good thing to shoot a streamlined bullet - but it won't really matter much, in terms of your ability to harvest game, unless you shoot at very long ranges

I will quantify a few bullets below to demonstate the differences:

Bullet/BC Velocity Drop 10MPH 15MPH KE

Fail Safe/.391 3000 16" 13.6 20.4 1786
Accubond/.507 3000 14.6" 10.1 15.1 2115
Barnes X/.552 3000 14.2" 9.2 14.2 2213
Barnes X/.552 2800 16.5" 10.1 15.1 1902

Accubond/.588 282016.0 9.314.0 2217

The top 4 bullets are 180 Grain, the guns are zeroed at 250 yds and the 10 MPH and 15 MPH columns are wind drift at 400 yds. KE is also at 400 yards.

The BChas a small effect on Dropless than 2 inches at 400 yds but a big difference in wind drift up to 6.3 inches. Most hunters think wind drift is a function of bullet speed, but the BC is much more important than speed. You will notice that theBarnse bullet lauched at 2800 FPS actually has 5.3 inches less wind drift than the FailSafe lauched at 3000 FPS while still having more drop. The KE is also greatly affected by the BC.

You will notice the Accubond/.588 in bold. This a 200 grain bullet it is lauched 180 FPS slower than the Failsafe and has less KE at the muzzle yet has the same bullet drop, 6.4 inches less wind drift, and over 400 LBS more KE than the failsafe @ 400YDS. With a high BC you may be able to shoot a heavier bullet at a slower muzzle velocity and have the same trajectory, and a lot more KE on target. So much for light and fast bullets on long shots.

I am big fan of high BC bullets in case it is not obvious. The biggest advantage it offers is it minimized the effects of wind on that critical first shot.

"Ballistic coefficient" is a numerical representation of a given projectile's ability to overcome air resistance, expressed as a fraction of the capability of a "standard projectile", which is assigned thevalue"1". So, a bullet that has a B.C. of 0.50 is half as efficient at overcoming air resistance as the standard projectile. Stated another way, if both the 0.50 B.C. bullet and the standard projectile wereboth fired at the same MV, the 0.50 projectile would lose velocity at twice the rate of the standard slug.

Basically, the B.C. figure is only valuable as a means of comparing different projectiles if you need to choose bullets that will carry the maximum amount of velocity & energy to long ranges. If you shoot factory ammo, this doesn't help you a whole lot! If you are a handloader, it can help you in choosing bullets for reloading. However, there are other factors about bullet performance that are generally more important for hunters - for example, penetration ability, weight retention, expansion characteristics, etc.

A lot of shooters get hung up on such things as B.C., when in actuality the differences in B.C. between different good hunting bullets means very little to people who kill most of their game within1,000 yards.....

IME, sectional density is more important to the hunter than balistic co-efficient.

Here's a little ballistic principle to ponder: You are out in the Bonneville salt flats. Perfectly level. You have a rifle mounted in a vise with the barrel perfectly leveled. Youalso have a bullet suspended at the muzzle of the rifle with an electronic release that allows that bullet to free fall downward at the exact instant the bullet coming down the rifle barrel exits the muzzle. Regardless of caliber, bullet weight, velocity, crosswind, or ballistic coefficient - both bullets willstrike the ground at exactly the same instant.

The issue is how far the bullet fired from the rifle barrel can travel before it hits the ground. Time of flight to the ground is always the same.

I agree. I do not mean to say BC is the most important factor to choosing a bullet because for hunting it is not. I just want to show how it can be a critical factor and all other things equal BC can significantly improve the performance of a cartridge and accuracy of a riflein hunting situations.

I agree completely - and I'm first in line willing to spend my money onthose streamlined projectiles like the Ballistic Tips, Sciroccos, Accubonds, etc; even if I rarely "need" them - like to get the best possible overall performance out of my ammunition.