One of the things that can be confusing to hunters is the variety of bullets available and trying to decide which is best. Ammunition companies and businesses that sell reloading products like to give names to their bullets that grab the buyers' attention.
Grand Slam, Trophy Bonded Bear Claw, Deep Curl, Hot-Cor, Ballistic Tip, Spitzer, Accubond, Partition, Spire Point, Scirocco, TTSX, and Core-Lokt are just a few examples of what is being advertised for the hunter each year.
With so many brands and types of ammunition available, it can be confusing to determine what best suits your hunting purposes. Would it surprise you to know that they all work pretty well and will do the job they were intended for?
First, determine how you want your bullet to perform. If you are hunting large, heavy game and the shots will be less than 150 yards, you may want a tough, heavy-round nose bullet that will generate a lot of energy and crush bone while continuing into the vital area, disrupting the lungs and heart.
However, if the shot must be taken at several hundred yards, you may prefer a lighter, more streamlined bullet with enough energy to drop the game at longer distances with a flatter trajectory than heavy round-nose bullets are capable of generating.
Often, when examining charts that list different calibers and velocities, there will be a small column marked "B.C." with a number included from .100 to .500. "B.C." stands for ballistic coefficient, and it is particularly important to those who shoot at 300 yards and beyond.
The ballistic coefficient of a bullet is a measure of its ability to overcome air resistance in flight. It is inversely proportional to negative acceleration. A higher number indicates a lower negative acceleration or that drag on the bullet is small in proportion to it's mass.
The formula for calculating the ballistic coefficient for small and large arms projectiles is: B.C. = M/d2.i
B.C.: Ballistic Coeficient
M: Mass
d: Measured Cross Section
i: Coefficient of form (can be derived by six methods)
Mathematically, it is the ratio of a bullet's sectional density to its coefficient of form.
If you understand this formula as well as I do, you are in trouble, because my brain became mathematically fried during geometry in high school, and I think this is trigonometry.
It isn't necessary, however, to understand trigonometry to understand how the density and shape of bullets affects the flight of bullets. Simply put, a heavier bullet will drop faster than a lighter bullet.
Also, round-nosed bullets create more wind resistance and slow down faster than Spitzer and Spire Point bullets, which have flatter trajectories due to less air resistance. This is true even if the Spire Point and Spitzer bullets are the same density as the round-nose bullets.
If the Spire Point and Spritzer bullets also have a boat tail, they will be even more stabilized and will have an even flatter trajectory over the effective lethal range of the caliber being used.
But you don't even have to completely understand that in order to pick ammunition that has an acceptable ballistic coefficient for the type of hunting you do, and the game you hunt. Just remember that the ballistic coefficient for bullets will generally be numbered from .100 to .500, and the higher the number the less drag there will be on the bullet in flight and the more efficiently the bullet will move through the air.
Thirty-caliber round-nosed bullets of 180 grains may have a ballistic coefficient of .200 or less, while the same caliber and density bullet with Boat Tail Spire Point construction can have a ballistic coefficient of .300 to .500.
Just for reference, a .30 caliber bullet that is intended for 400 yards or more should have a ballistic coefficient of .325 or more in my opinion. My own reloads for my .300 Weatherby Magnum use a Boat Tail Spire Point bullet with a ballistic coefficient of .500.
However, that bullet is a little longer in order to achieve that B.C. The longer neck of the Weatherby case allows me to seat the bullet so that the overall length of the cartridge is consistent with Weatherby specifications without packing the powder in the case tighter. So far, I have not reloaded for my .30-06 but have purchased commercial ammunition that has a ballistic coefficient of .370. Both rifles and the ammunition I use when hunting have performed very well.
Smokey Merkley was raised in Idaho and has been hunting since he was 10 years old. He was a member of the faculty of Texas A&M University for 25 years. There he taught orienteering, marksmanship, self-defense, fencing, scuba diving and boxing. He was among the first DPS-certified Texas Concealed Handgun Instructors. He can be contacted at mokeydo41245@hotmail.com.
