How to Easily Sight-In Your Rifle with a Point-Blank Zero
Setting up a standard variable-power scope with a duplex cross-hair reticle with a point-blank zero is a smart choice for hunters. (Bill Buckley /)
Modern precision rifle scopes are powerful tools that can be quite effective for hunters who take the time to master them. Exposed elevation turrets combined with reticles that have reference marks for holdovers and windage can take the guesswork out of connecting on longer shots.
But these scopes aren’t without their drawbacks. The faint lines in the reticles can be difficult to see in low-light conditions and tough to decipher in the heat of the moment. Hunting with them requires time and practice to master. Because there’s no shortcut when it comes to using them—you’re either all in, or better off going another route.
This is why setting up a standard variable-power scope that has a duplex cross-hair reticle with a point-blank zero (PBZ) is a smart choice.
The idea is simple. You zero your rifle so that it hits a bit high at 100 yards. Depending on the distance and the size of the target, this allows you to place the crosshairs in the middle of target and not have to worry about fiddling with turrets of calculating holdovers.
Typically, you’ll want to set your zero around 2 to 3 inches high at 100 yards. With most cartridges, this will put you dead-on somewhere between 200 and 245 yards, and a few inches low around 280 yards.
So, if you’re hunting a whitetail in open country, for instance, this means you can hold right in the center of the chest as long as it’s within 300 yards.
To set up your PBZ, you’ll need to use a ballistic calculator (there are many free ones online) and gather some basic information about your rifle and ammunition. You’ll want to know your muzzle velocity, the ballistic coefficient of your projectile, and some measurements such as how high above the bore the center of the scope is, and the twist rate of the barrel.
You'll want to measure how high the center of the scope is above the bore for an accurate point-blank zero. (Bill Buckley/)
Once you plug this information into the calculator, you can fiddle with your zero height to come up with your ideal PBZ.
With the 6.5 PRC you see pictured here, the rifle shoots the 143-grain ELD-X bullets at 3015 fps. My point of aim was the center of the circle in the black square, so my rounds are impacting 2 inches high. According to the calculator, this puts my point of impact dead on at 235 yards and 4.1 inches low at 300.
The author's point of aim was the center of the circle in the black square, so his rounds are impacting 2 inches high. (Bill Buckley/)
Given that the vital zone of a whitetail is about 8 inches, this means that for any buck that’s within that range, I can just hold on the center and shoot. Even if there’s a 10-mph crosswind, the bullet will only drift 4.3 inches at 300, so with a minimal correction for that, I don’t need to be too concerned about windage.
The beauty of this system is its simplicity. More than once I’ve been in the field with a hunter who had a complicated scope on his rifle, and who also had to fiddle and fuss with his calculations as precious seconds ticked away. Meanwhile, the animal moved out of range or out of sight.
Here’s a bonus tip. You can still use this system with complicated precision rifle scopes—which is something I often do. Let’s say I’m running a 3-18X first-focal plane tactical scope that uses milliradians on my rifle. Even though I zero my rifle at 100 yards, while out in the field I’ll often dial it up .6 mils, which puts the point of impact just above 2 inches at 100. This gives me the same quick point-and-shoot capability on game within that 300-yard zone, and if for some reason a longer shot presents itself, I can either try to stalk closer or take the time to adjust my scope to make a more precise shot. For me, this offers the best of both worlds.