Sighting In Your Rifle

Once a rifle is sighted in, it no longer needs to be adjusted. That belief, however, is remarkably wrong. Here are detailed instructions for rifle sight adjustment.

I've encountered too many situations at the shooting range where someone complains about not being able to sight in their rifle. The group isn't small enough, and there are always a few "flyers." Strangest of all, the sighting distance is usually only 75 meters.

The most common problems are the wrong shooting position and insufficient support for the firearm. Try shooting a proper five-shot group with the rifle's forend on a log, the left hand gripping the forend, and the buttstock supported solely on the shoulder. You are doomed to fail.

One oddity is that shooters start making adjustments based on a single shot. That's wild because only after at least three shots does the group indicate the point of impact. A single shot might just have been off. Making adjustments based on that single shot will surely mess things up. Don't skimp on the cost of ammunition; shoot proper groups with the exact cartridge you intend to use for hunting. If you can't produce proper groups, practice, practice, and then practice some more. The issue might lie in poor trigger control.

Additionally, many wonder how much one click on the scope turret affects the adjustment. Most of the riflescopes in Finland are old 20th-century American scopes. Many of them have no markings whatsoever regarding the impact of clicks. Furthermore, the impact of clicks is often calculated based on a 90-yard (82.3 m) shooting distance. It's not easy to figure out the required adjustment in clicks for a 1/8 MOA (3.04 mm) scope when shooting at 150 meters.

When purchasing a scope, ensure that the adjustment turrets read 1 click = 0.1 MRAD or 1 cm at 100 m. That means one click equals 1 cm at 100 meters, 1.5 cm at 150 meters, and 3 cm at 300 meters, etc. Most Europeans find using a mil-radian-based scope easier than MOA or inch-based scopes. It's also worth remembering that 20th-century scopes are downright poor in optical quality and coatings compared to modern scopes.

Three-point support

Proper bedding of the firearm is paramount when sighting in a rifle. The easiest way to do this is by placing a sandbag under the forend (or using a bipod) and under the buttstock, with the left hand lightly supporting the buttstock. Remember, the left hand (for a right-handed shooter) should not grip the forend.

Once the rifle butt is securely pressed against the shoulder with suitable force, the rifle is supported at three different points. You can test the effectiveness of the bedding as follows: when the reticle is aligned, gently release your grip on the rifle. If the reticle remains in place, everything is fine.

Then, you can focus on the trigger pull. Remember that the trigger pull is done with the fingertip, not the finger's first joint, and the pull should be straight back. The recommended grip is to keep the thumb straight alongside the pistol grip. If you wrap the thumb around the pistol grip, it may move during the trigger pull. This is a mistake that I regularly see, especially when shooting larger calibers. Finally, remember that the trigger pull should be a smooth squeeze, not a jerking motion.

Cold bore sighting

Here's how it goes: you place the rifle on a solid support, such as sandbags. Then, remove the rifle bolt. Set up a target at a hundred meters and aim the rifle so that the black center of the target is visible in the middle of the barrel when you look through it. Next, look through the scope, steady the rifle, and center the reticle as precisely as possible. This is where confusion may arise because the adjustments work the opposite way. Adjust the elevation turret upward if you want to lower the reticle during cold bore sighting. Adjust the windage turret to the left if you wish for the reticle to move to the right.

Another option is to use a laser bore sighter, which saves at least a few rounds. Gently place the bore sighter in the barrel, turn on the laser, and aim the rifle so that the laser dot is in the center of the target. Adjust the reticle accordingly and start shooting.

Choose a target with a reasonably small bullseye; air rifle targets are great. At this point, shooting from the support you'll use in real situations is crucial. If you shoot with a bipod, it's not wise to sight the rifle on top of sandbags because the point of impact can change drastically. If you're a treetop hunter, use the backpack you'll have with you in real situations as support.

Next, fire three shots with great care. Check the impacts on the target and determine the point of impact (POI). Here's how to do it: Draw vertical and horizontal lines through the group so that there is an equal number of bullet holes on each side. The intersection of the lines is the center of the group. Ignore any distinguishable flyers. Then, make the necessary adjustments with the adjustment turrets and fire another three rounds. If you did the measuring and the adjustments correctly, the group would be in the center of the target. Take your time and focus on what you're doing.

When the shots are in a small enough group (sub 1 MOA or 3 cm) in the center of the target, it's time to zero the scope. Do this by first releasing the elevation adjustment turret (read the manual carefully on how to do this), zeroing the adjustment turret setting, and tightening the adjustment turret in place. Repeat the same process for the windage adjustment, then fire a test shot. If the bullet hole is in the center of the target, your rifle is correctly sighted in. A well-sighted rifle builds confidence, and that's what you need when the moment for a crucial shot comes.

Correct sighting distance

Now, I can only wonder about the most common sighting distance of seventy-five meters. Shooting distances in moose hunting are indeed short, usually under fifty meters. However, the situation or circumstances may require a shot at 150-200 meters in whitetail and roe deer hunting. Even when stalking moose in a field, the shooting distances are far greater than 75 meters, and treetop hunters rarely shoot any closer than 150 meters.

Even for moose hunters, it's worth utilizing all the bullet's ballistic features. It's time to familiarize oneself with the concept of Point Blank Range, which can be described as an invisible "tube" in which the bullet flies within given tolerances. Let's take, for example, the Norma Oryx, 11.7 grams, 180 grains, muzzle velocity 790 m/sec. The scope height is 52 millimeters above the bore axis, and we want the bullet to fly within a four-centimeter "tube."

We chose a sighting distance of 150 meters simply because it's a distance that can be sighted in at most shooting ranges. The Norma ballistic program tells us that at 38 meters, the bullet reaches the aiming point, and the trajectory is still rising. At a hundred meters, the bullet is three centimeters above the aiming point; at 150 meters, it's on the aiming point again; and at 175 meters, the bullet has dropped 3.6 centimeters.

These values are sufficient even for treetop hunting. Knowing that at 200 meters, the bullet has dropped 8.4 centimeters, it's adequate for a shot at a moose, even if you aim for the center of the shoulder. A bullet fired horizontally at 150 meters will hit the ground approximately 444 meters away, still carrying 1325 joules of energy. Forget the 75-meter sighting distance. Forget it also because, at 150 meters, you'll know your actual shooting skills much better than at a short range.

When should you sight in your rifle?

Re-sighting is necessary when switching between cartridge brands, bullet types, or bullet weights. Even if the bullet weight remains the same, a new bullet may behave differently in the barrel compared to the old one. Sighting in should always be done after the rifle has been stored for a long time and also when the rifle's operating temperature changes. A rifle sighted in during the summer heat will undoubtedly hit differently in the autumn chill. When you go on a hunting trip, always sight in the rifle on-site to ensure it shoots where it should.

Sighting in the rifle in prevailing conditions is the key to a successful game shot. The more often you check the rifle's performance, the more shooting practice you'll get. This will soon be reflected in the quality of your game shots.

TIP:

Always aim to sight in the rifle with as few shots as possible because the more shots fired with the rifle, the more barrel fouling and heating affect the point of impact. It's best to shoot sighting shots when the rifle has fired about 10-20 shots after a thorough cleaning and has cooled back to ambient temperature. At this point, copper and residue have filled the tiny imperfections in the barrel's interior surface and rifling, which were exposed during cleaning, resulting in smooth operation of the rifle. There's even an old saying among sharpshooters: "Never go to war with a completely clean rifle."

This article was originally published in Riista magazine. Text and photos: Juha Jormanainen