If you are planning on hunting big game this year with a rifle, I assume you know what caliber of rifle you plan to use. There are certainly many fine choices of rifle calibers to choose from depending on how far you expect to have to shoot, how much retained energy you want the bullet to have at impact, and how much recoil you can comfortably handle.
In this column, I'd like to focus on what you expect from the cartridge and caliber you will be using this year. Also, to keep the column from being unnecessarily long, I'll focus on the .300 WBY Mag and 180 grain bullet, because it is the big game rifle and bullet I normally use if I have tags for both deer and elk. I think the information will be useful regardless of the caliber and bullet weight one chooses.
To start off, Weatherby loads several different .300 WBY 180 grain bullets such as Spitzer, Spire Point, TTSX, Ballistic Tip, AccuBond, and Partition, with ballistic coefficients (BCs), ranging from .331 to .507. The muzzle velocities of each of those 180-grain bullets are very similar, but the efficiency with which they move through air resistance and their accuracy at distance is a function of their construction and specific BC. For example, if I sight a 180 grain Spitzer bullet with a BC of .331 to hit 3.6 inches above the point of aim at 100 yards, it will hit point of aim at 300 yards and will be 30.9 inches low of point of aim at 500 yards. However, if I use a Spire Point bullet of the same weight with a BC of .475, at 3.1 inches above point of aim at 100 yards, it will also hit point of aim at 300 yards , but will only be 24.4 inches low at 500 yards. Again, if I use the same weight TTSX or Ballistic Tip bullet with a BC of .507, at 2.8 inches above point of aim at 100 yards, it will hit point of aim at 300 yards, and will be 22.4 inches below point of aim at 500 yards.
When sighting in my rifle prior to hunting season, I shoot hand-loaded ammunition with 180 grain Swift Scirocco II or 180 grain Hornady ELD bullets to 3,120 feet per second muzzle velocity. Both bullets have a BC of .520. I sight in to hit 2.9 inches above point of aim at 100 yards. The high BC of those bullets makes them slightly above point of aim at 300 yards and about 6 inches low at 400 yards and around 20 inches low at 500 yards. I am able to aim at the center of the vital zone and place a lethal shot all the way out to 400 yards. If I decide to shoot beyond 400 yards, the bullet still retains 1,500 foot-pounds of energy at 800 yards. If you were wondering, I won't try to shoot that far, but 20 inches low at 500 yards is pretty easy to compensate for by raising the cross hairs of my telescopic sight to rest higher in the vital zone or right on top of the game's withers out to 500 yards or a little more if I'm certain I can make the shot.
Once a hunter knows what can be expected from the ammunition being used, deciding whether to shoot for center of the vital area or hold a little higher becomes easier.
For shots in excess of 300 yards, I really like a good telescopic sight because I can shift the crosshair where I want with out losing sight of the game itself.
Even though I load my own ammunition with bullets that have a high ballistic coefficient, there is nothing wrong with buying your ammunition as long as you know what you can expect from it and sight in your rifle accordingly.
Hopefully, you can see how spending some range time with your rifle and ammunition will get you familiar with the ammunition you will be using so you know how it will perform when you get the opportunity to use it in the field.
Most ammunition manufacturers will tell you what the BC of the bullets is. If not, you can probably look it up on the internet or ask your local gun shop if they have some ballistic tables you could look at. The bullets with the higher ballistic coefficients will have Boat Tails and Spire Points or polymer Ballistic Tips to create less air resistance when fired.
Have a safe, productive hunting season this year.
Smokey Merkley was raised in Idaho and has been hunting since he was 10 years old. He can be contacted at mokeydo41245@hotmail.com.
