Determining Holdover Value with Your Rangefinder
So you have your rifle zeroed in at 100 yards, and on the range you can consistently group bullets near or in the bull’s-eye. But now you’re hunting and that deer is standing out there well over 100 yards, maybe twice that far, maybe even more, so where do you aim? How do you calculate hold-over?
Hold-over, or hold-over value, is the adjustment you would need to make, essentially aiming high to account for bullet drop at longer ranges, to hit a target beyond your sight-in distance, according to Vic Ziliani, Bushnell’s communications coordinator.
To determine hold-over, you should first accurately determine distance to your target, and that means a good laser rangefinder. Also, before going afield you should consult the ballistics chart for the ammunition you will be using. Usually the chart is printed on the ammunition box, but if not you can look it up on the manufacturer’s website. Either commit the numbers to memory or print out a version of the chart small enough to tape on the stock of your rifle, where you can easily refer to it.
The chart will give you the amount of drop that bullet will experience at different ranges compared to a set zero distance. For instance, the 85-grain bullet in Federal Premium’s Barnes TSX ammo, zeroed at 100 yards, will drop 2.7 inches at 200 yards, which would not require much adjustment to hit a deer’s vital zone, but at 300 yards the bullet will drop 10.3 inches, which would require a significant hold-over to assure the bullet drops into the zone.
“Always practice these types of shots on targets before shooting at an animal,” Ziliani said.
But distance isn’t the only factor affecting your aiming point. Angle of the shot, whether shooting uphill or downhill, also comes into play.
There are numerous explanations available about the uphill/downhill effect on bullet trajectory, but the shortcut version is gravity has less effect on uphill and downhill shots as it does on flat horizontal shots, meaning bullets will hit higher on angled shots, plus there’s the trigonometry factor of triangles, angles, hypotenuses…STOP!
Before it gets too confusing, too mathematically complex, know there is a simple solution to determining hold-over on any shot, horizontal, uphill, or downhill, and that is to use a laser rangefinder with angle range compensation (ARC).
“Most modern LRFs can give you true distance to the target or angled compensated distance up or down in the mountains or out of an elevated stand,” Ziliani said. “It calculates the true horizontal distance into adjusted angled distance.”
In short, the hold-over value is determined for you, displayed nearly instantly on your rangefinder screen. But what if your rangefinder doesn’t have ARC? Ziliani’s answer is simple. “Please consider upgrading your LRF—most if not all LRFs have this feature—now,” he said.
Reasonable prices and well worth it if I don’t have to calculate trigonometry, let alone mathematics, while I’m trying to line up a shot.
Content provided by Bushnell