Ask a group of hunters how they sight in their rifles and you will get as many answers. “An inch high at a hundred.” “As long as it hits a pie plate.” “Nuts on at 200.” Although some of these are better than others, none of them are technically wrong—and all of them can be made to get the job done. However, the best way to sight in your rifle—especially if you may have to make some longer shots—is to establish your maximum PBR.
What is PBR?
PBR stands for point-blank range, which is the distance at which you can simply place the reticle on your target and still strike the vitals without making any elevation adjustments for distance. Maximizing your PBR will make you a much more effective shooter in the field. Even if you are versed in how to adjust your elevation turret to account for distance and you have a dope card for your cartridge load with you, you still may not always have time to make the adjustment before your window of opportunity disappears. But if your target is within your PBR, all you need to do is point and shoot.
How to establish your maximum PBR
To establish your maximum PBR, you will need two things: the size of your target’s vitals and the trajectory of your bullet. If you have a graphical curve of your bullet trajectory, simply adjust the curve so that the high point of the curve is half the diameter of your target’s vitals above line of sight (the x-axis). This way, if you place the reticle over the center of your target’s vitals, at no point will the bullet ever get above the top of the vitals. Next, find the point on the curve half the diameter of your target’s vitals below the x-axis. This is your maximum PBR. Beyond this distance, the bullet will fall below your target’s vitals and make a less lethal hit—or even miss altogether—unless you complete a hold for elevation or adjust your sight. Now, zero your rifle to the distance at which the curve representing your bullet crosses the x-axis. Once complete, you will be able to simply point and shoot at the center of the vitals on any target within the maximum PBR distance and score a hit.
If you don’t have a graphical representation of your bullet trajectory, take the muzzle velocity and ballistic coefficient and put them into a ballistics calculator like the one pictured above. Play around with the zero until the maximum trajectory or bullet drop—different calculators will use one or the other—in inches is half the diameter of the vitals. As you can see in the above, this is between 150 yards and 175 yards. When you find the right zero, your maximum PBR will be the distance at which the come-up is “minus” half the diameter of the vitals (the minus signifies that you are below the line of sight). Sight your rifle in to the distance you set as the zero on the ballistics calculator. Once complete, you will be able to simply point and shoot your rifle at the center of the vitals on any target within the maximum PBR and score a hit.