Learning how to tune a scope to a rifle is an important skill every marksman needs.
Working in and touring leading firearms factories has given me some interesting insights into what it takes to make a quality long-range rifle shoot the same from gun to gun, from one day to the next. Gun companies who build sniper systems for the military know how to tune a scope to a rifle.
While roaming around the shop area of a leading manufacturer of military sniper rifles, I noticed a large chart on the wall with an array of horizontal lines. I put the location of the chart together with the scope mounting area across the room. The chart helped check calibration of mounted scopes.
Getting Perfect Alignment
Shooting long-range rifles that require dialing in windage and elevation corrections requires that the scope’s crosshairs being perfectly vertical and horizontal to the bore’s axis. Now this won’t make much difference if you sight your rifle at 100 yards and shoot at a buck at 150 yards, but it can mean the difference between life and death if a sniper’s rifle and scope are not in perfect harmony.
One way to assure that your rifle and scope are aligned correctly is to shoot, adjust your scope through its elevation range and shoot again. Bulls Bag introduced their Dead Nuts/ Dead Zone target to help get the job done right.
“Our goal at Bulls Bag in designing this target was to apply the science of ballistic fingerprinting to achieve the best possible accuracy from your rifle,” the company’s Vice President of Marketing William Sullivan said.
“Dead Nuts/Dead Zone shooting target technology system will make you vastly more proficient during your limited range time with the use of our rifle target. An operational target for shooting is the only known diagnostic check for the operational rifle, and can be used to quantify the claims of a new rifle system with use of our shooting range target.”
First Things First
Long-range shooters know the practice of shooting at 100 yards often lacks practical application once in the field. “There is rarely anything more disappointing to a shooter than identifying a problem with a rifle system. Especially, after a full day of gathering ballistic data at the shooting range or especially during a hunt,” Williams said.
“What makes this calibration targets valuable is that you must understand that all rifles and their components have acceptable tolerances in the machining process. Scopes have erector springs, reticles and tolerances within their bullet drop compensating turrets. Rifle barrels are machined, chambered and threaded. Rifle receivers are cut from steel blanks threaded and tapped for scope mounts. Then you have all the mounting hardware with their acceptable machining tolerances. Combining all of these components can produce a system that is out of square or lacks concentricity.”
Looks May be Deceiving
For example, a scope’s reticle may appear level, but an acceptable tolerance for the manufacturer is 3 degrees. This error is magnified exponentially by the distance to the target. This is most noticeable at long-range shots while shooting targets. It’s easy to dismiss this as wind deflection or external ballistic factors, but many rifles have a straight tracking issue. This means that the ability of the reticle to adjust directly at a 90 degree angle. The Dead Nuts target offers two vertical straight tracking channels to check a scope’s ability to track correctly.
Let us suppose your 1/4 MOA scope is truly a .28 MOA click. One click should move a bullet impact .25 MOA at 100 yards. This 3/100 of an inch difference at 100 yards magnifies itself with distance. If it’s off this much it will eaual 10.8 inches of difference just in scope tolerance with 15 MOA of elevation placed on the scope for a 600 yard target. Match your scope’s true click value to the rifle’s ballistic drop table and you will experience exact adjustments for all shooting ranges.
It Works!
Putting the target to use, I mounted it at exactly 100 yards and made sure that it was level. Following the simple instructions printed on the target, I shot a 3-shot group within the vertical track. I then adjusted the scope to the bottom of its elevation adjustment, then shot another group. The same practice follows all the way through to the peak of elevation adjustments.
If the groups stayed within the track, then the scope is in alignment. If the groups print outside the tracks, rotate the scope to come in line with the vertical tracks. After moving the scope, repeat the process in the second vertical track to double-check the adjustments. At the same time you move the elevation adjustments, you are keeping track of the “clicks.” That assures the accumulation of actual click value equals the appropriate distance in minutes of angle, or inches, on the target.
You will learn that some scopes have “strong” or “weak” clicks due to manufacturing tolerances within the scope. This information entered into your notes will make for precise “dope” corrections for your ever-changing shooting range conditions.
Putting a Dead Nuts/Dead Zone target to work is the best way to tune a scope to a rifle.
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