WHAT'S YOUR POINT-BLANK RANGE?
“Point-blank” is a common term associated with firearms, yet it’s been distorted by popular culture as meaning an extremely short distance. Not exactly the case.
The term has been handed down to us from the French pointe-a-blanc, an old phrase that meant a firearm—probably a cannon—could be pointed directly at the small white spot on the target, with no more elevation added than was built into the gun already. In other words, with no holdover.
For modern hunters, the meaning is much the same. Point blank is the maximum range at which you can hold dead center on your target—with no elevation adjustment whatsoever—and still hit within the intended target area at any distance between the muzzle and that maximum range. The distance at which the projectile will do this varies greatly depending on the trajectory of your cartridge and the size of the target.
For demonstrative purposes, consider a Federal Premium 30-06 Sprg. Sierra GameKing 165-grain. The scope is mounted, on average, 1 ½ inch above the line of the bore. Therefore, the barrel must be elevated to some degree (in comparison to the line of sight) to have the bullet rise to cross the line of sight, continue on an upward arc for a particular amount before gravity works its magic and back down to re-cross the line of sight. The distance at which the bullet re-crosses the line of sight is known as the zero, and can be chosen by the shooter to best manipulate the trajectory for his or her own purposes.
How do we best manipulate the trajectory of our rifle? That depends on our intended objective. Use deer hunting for an example. On most deer, we can assume a vital zone of five inches. To place a bullet within that five-inch circle of vital tissue, we should first determine the proper zero, where the midrange trajectory doesn’t rise any more than 2.5 inches (half the vital zone distance) above the line of sight. After that, we can look at the detailed trajectory curve to find out at what distance our bullet is no more than 2.5 inches below our line of sight. This indicates that a hold on the center of a deer’s vital zone will put in a bullet in the proper spot.
With a 200-yard zero, the 30-06 Sprg. Sierra GameKing 165-grain Federal Premium load mentioned earlier rises a maximum of 1.7 inch above the line of sight. However, assuming that 5-inch vital zone, we can push the envelope a bit, and use a bit more midrange rise.
Find The Sweet Spot
The Federal Premium Ballistics Calculator reveals that a zero of 220 yards lets the bullet rise exactly 2.5 inches at 140 yards, and drop to 2.5 inches below the line of sight at 255 yards. This means that any for deer between the muzzle and 255 yards, you would simply hold the crosshairs on the center of the vitals and squeeze the trigger. The calculator also notes that the 100-yard trajectory is 2.4 inches above the line of sight, which is helpful to know if you need to check your rifle’s zero where you don’t have access to a 220-yard range.
This is just one example, but you can use the same tools to make a decision for your chosen rifle-ammunition combination. If you’re hunting elk or moose, the vital zone is certainly larger, or if you’re sniping prairie dogs, it will be considerably smaller. Faster cartridges will offer a flatter trajectory than their counterparts, just as the slower cartridges for lever-action rifles will have a shorter point-blank range.