Sighting in Your Rifle
To make a good shot you need to know how your rifle shoots.
By Terry Erwin
Some things in deer hunting should not be done at the last minute, and sighting in your rifle is one of them. By “zeroing in— your rifle well in advance of hunting season, you ensure yourself, and the game you are seeking, that you can make a responsible shot.
The first step is to “bore sight— the rifle. After making sure it is safely pointed and unloaded and the scope is focused for your eye, bore-sight the rifle using a bore collimator, which slips into the muzzle end of the barrel and allows you to adjust the scope crosshairs on a graduated grid. Once your scoped rifle has been bore-sighted, gather hearing and eye protection, a pair of binoculars or a spotting scope and head to a shooting range with a safe backstop that offers both 25- and 100-yard firing positions.
The performance of any rifle varies with different brands of ammunition. Use at least two types of commercially manufactured ammunition with the same bullet weight and design, and approximately the same muzzle velocity. Even identical rifles of the same caliber shooting the same ammunition may have different impact points on a target when finely “tuned— and sighted-in. Each rifle will “like— a certain kind of ammunition. Once you find it, stick with it, whether it is a commercial load or a favorite hand load.
Start at the 25-yard position and put up a large 100-yard paper target, preferably with one-inch grid squares across the entire target and a large bull’s-eye center. Use a sturdy shooting bench with sand bags or a commercially made shooting rest. Rest the forearm or rifle forestock on the sand bags. Resting only the barrel on a solid object will usually cause the rifle to shoot high.
Leaving the safety on, load one round into the magazine and allow the bolt to pick up the round and place it in the chamber. Put the crosshairs directly on the center of the bulls-eye. Before you shoot, close your eyes for about five seconds and then open them. Did the crosshairs drift off the center of the target while your shooting eye was closed? If so, adjust your position and try again. If the crosshairs are still centered, you are ready to shoot.
Move the safety to the “off— position and take in a deep breath. Let about half of it out and hold it. Now gently squeeze the trigger until the rifle fires. You can probably see the bullet hole through your riflescope, and certainly through the spotting scope or binoculars. If it hit the center, then fire another two rounds for confirmation.
If the hits are not centered on the bull’s-eye, move your scope’s internal adjustments vertically or horizontally to the desired impact point. Most variable scopes have internal adjustments in 1/4-inch increments (minutes-of-angle or “clicks—) at 100 yards. Remember, you are at 25 yards, so you will have to multiply the number of clicks times four. Repeat the process until the hits are centered on the target. If all hits are right on target, then move a fresh target to the 100-yard distance and start over.
At 100 yards, repeat the process in the same fashion. Carefully fire one round, and check for the hole. Fire another two rounds and adjust the scope to the center of impact if necessary. Now shoot another careful 3-shot group, making sure that the barrel has time to cool between shots. Shooters usually sight in their rifles to hit 1 1/2 - 2 inches above the point of aim at 100 yards. In other words, you should aim exactly at the center of the bull’s-eye and the bullets should land about 1 1/2 - 2 inches directly above the center of the bull’s-eye. Did the center of the group move so that it is now 1 1/2 - 2 inches over the point of aim? If it did, good enough; if not, carefully repeat the steps.
Never rely on how a rifle shot last year. Even a single jolt can knock the alignment off during the off-season. Sighting-in makes you practice, helps you detect problems with your shooting technique and builds confidence in your shooting ability.