Setting aside all other elements in terms of getting a rifle and sighting system up and running the proper zeroing of that firearm is front and center the most important element involved when getting accurate target contact hits. The rifles zero is in effect the exact point the bullet meets dead center on a paper target at 100 yards or less. In general, the 100-yard figure is used to act as a general standard when zeroing a firearm as it is the point at which additional “DOPE”, or (Data Of Previous Engagement) is recorded.
Even the tops of scope protective caps and turret heads will often indicate in print that ¼ inch is the movement of the optical systems crosshairs per individual click at 100 yards when MOA graduations are employed. This information is used for the most part after a correct zero has been successfully completed.
Obtaining a basic zero
First of all, when zeroing a rifle the shooter needs to make use of a solid surface. This is not the time for a off hand free swinging slap at the target than expecting positive accurate results in the process of using this aiming method. Here the use of a bench rest table or at least a prone position shooting mat is required. For my money, the bench rest is not only best, but I also carry a portable bench rest setup in my truck at all times just to cover these kinds of situations afield. Keep in mind I will at times cover up to five or six new firearms in the space of 30 days being weapons review is paramount regarding the tasks associated with a gun writer.
Assuming you have a solid rest also make us of a good shooting bag with rice or sand filling, or even one of the plastic support bench stands now available almost in every gun shop across the country.
Selecting ammunition for your zeroing event stay as close in grain weight regarding bulletsou will use in the field as possible, and also pay attention to bullet design. Keep this element of the task consistent can aide greatly when obtaining a correct zero and than proceeding to push yours effective range to some extended limits.
For this example, I have selected the Riton 3 TACTIX rifle scope which is built by Riton, and makes use of the military grade optics companies special high grade mounts and rings which are critical in keeping everything lined up correctly. The rifle used in this case is the Mossberg Scout rifle chambered in 308 Winchester. This is an actual required zero setup in this case, being the rifle is going to be taken afield this fall as a backup system to several brand new rifle designs being tried on trophy whitetail deer along the Missouri breaks of western South Dakota.
Being the rifle makes use of the Weaver style rail and that is a match to the Riton Tactical base and ring system, a quick check of mount tightness and alignment was a snap and a requirement during this basic undertaking. When all was good the bolt was removed from the Scout rifle make a straight through look down the bore at a target mounted at 25 yards possible. This is called direct bore sighting and a very fast and easy way to match the exact point of the cross hairs on the target face to the exact point of the bore in real time when shooting a bolt action rifle.
While looking through the rifle barrel from the rear line up the barrel with the center of the target down range. Set that target at 25 yards in terms o muzzle to target distance. Now keeping the rifle dead still turn the windage and elevation adjustment knobs so as to move the cross hairs to the exact impact point at which the barrel is now alined (target center.) Reinstalling the bolt chamber a cartridge and shoot a round for an exact impact point mark on the target. In general that point will be at least on paper, but in some cases very close to the bulls eye.
In the case of the Riton tactical X3 the click adjustments over the bullet impact 1/2” per click at 100 yards, that means at 25 yards you need to up those clicks by a factor of four and that also means a lot of turning on the adjustment knobs if your quite far off the dead on zero point.
When the 25 yard zero is established the shooting can be moved out to 100 yards. If don’t correctly you should b on the paper at that range. If alignment is correct the bullet will be coming in at about three inches high. ( Most high velocity big rifle cartridges.) Now a simple click down a few turns and your in business.
There is still another method to zero a rifle, and that is what is call the two shot system. Here you set the rifle in a firm vice or sand bag rest. The rifle can not move during this process so using a bench and solid rest is required here at all times.
With the rifle mounted in a solid fashion fire a round with the cross hairs on dead zero. Bore sighting is a good idea prior to taking this shot. Now, finding the impact bullet hole mark the spot with a good black marking pen. Now, go back to the rifle and with it locked down on the bench and still aimed at the bull eye start turning the windage adjustment knob in the direction of the bullet hole. Lets say the hit was four inches to the left. Click four inches to the left by watching the cross hairs move in the scope with the rifle dead still in its rest.
When the cross hairs are alined with the bullet, but the bullet hole is still five inches high don’t move the rifle at all, but turn the elevation knob up and watch the cross hairs move in the scope right to the bullet hole. With that task completed you have just zeroed your rifle. Fire a test group for conformation and go hunting. If you trust your shooting one round will do the deal.