The Art of Sighting in a Scope
Ask any seasoned hunter and they will almost always agree that in most cases you should spend more money on a quality scope than what the firearm cost. Today's scopes, even in the less expensive ranges have drastically improved clarity, light gathering and recoil resistance. One thing is a given no matter what the cost and quality of the scope though, if not mounted correctly and properly zeroed in, they will not deliver accuracy in the field.
In today’s tip, we will discuss the basics of proper scope preparations.
Let’s review the basic scope and descriptions of the features. The power is the rating for how much the optics magnifies the image. The ratings are based on the 1 power per 25 yards concept for most scopes. The most popular scope on the market is a 3-9X variable.
Eye relief is the distance your eye must be from the lens to get a full view through the scope and is usually stated in a range of inches. The distance between the end of the scope and your eye is a key component to sighting your rifle scope. You will need to make sure that the distance between your eye and the scope is far enough so that upon firing a shot the recoil doesn’t send the scope back far enough to make contact with your eye.
Light transfer is very important when shooting in lower light conditions. Clarity and distortion is a product of lens quality. The Objective lens (front lens) size has a lot to do with light transfer, clarity, and distortion. The bigger the objective lens, the better, to a point. Larger lenses require higher mounts to clear the barrel. But there are many factors that could affect light and clarity.
Field of view is the width of the view in yards, at 100 yds distance. The wider the better and the easier it will be to spot the target. The more powerful the scope, the narrower the field of view.
Parallax is basically when the crosshairs appear to move on the target when the rifle is stationary and your eye moves. Some scopes have a parallax adjustment, If your target is at 200 yds, make sure the ring is set for 200 yds, otherwise, you will still get parallax.
Reticles are sometimes called crosshairs. Ideally, you want them heavy enough to see in subdued light and thin enough so they won't blot out the target.
Now let’s get that thing mounted. It is best to secure the firearm in a gun vise or bench. Make sure your bases and rings are compatible with your scope and gun model or any pre-drilled holes. Follow manufacturers instructions for proper mounting. Make sure that the eye relief is properly set for the end-users arm length and style of shooting. Also, make sure crosshairs are square to the horizon.
Next, if you have access to a laser or bore sighting tools proceed with adjusting your scope crosshairs to get on the paper at 50 yds.
Time to put a few rounds through the gun. It is imperative while performing a sight in to use a shooters bench or vise to have a consistent repeatable test pattern. Most recommend at least three-shot groups with some barrel cool downtime between shots. Using the maximum power that delivers a clear image take your test shots at 50-100 yds and view results. There are a lot of discussions on how to obtain the quickest zero on a scope, but the following method has worked for me and several of my companions. Measure in inches how far off your group (Point of Impact) POI was from the center and adjust your scope until the crosshairs of the reticle are right on the center of the three-shot group. In the image below, you can see how the adjustments work to bring your tight grouping to the center of the target.
Continue fine-tuning keeping in mind that for most common deer calibers you should be hitting between 1 and 2 inches high at 100yds for approximate zero at 200 yds give or take.
It’s always best every year after your gun gets put up after the season to test-fire a round or two before heading to the woods the next season. Be sure to check back in next week for more tips and tricks from our Pro Staff around the country.