How to Use Side Focus in Nikon M-308

Many people who have scopes are primarily familiar with adjustments made with the windage and elevation knobs. The elevation knob is located on top of the scope, and usually, it moves the reticle up and down.

However, the windage knob is basically on the right side of the scope, and you can move the reticle left and right. , you have the third knob on the left side of the scope.

This is your side focus. The critical question is What is a side focus on a scope? Here in this article, we will explain the side focus or parallax adjustment knob.

Nikon M-308 overview:

The Nikon M-308 Rifle Scope is specially designed for long-range and with the famous 308 AR platform in mind. The M-308 is powered with different features that will prove themselves repeatedly in the field or at the range.

The fully multi-coated lenses of Nikon and Ultra ClearCoat optical systems usually deliver superior image clarity and resolution. It has up to 95% light transmission.

The NikoPlex Model characteristics Rapid Action Turrets are calibrated for the trajectory of the .308 NATO Match round with 168-grain HPBT bullets that permit the shooter to dial in known distances out to 800 yards.

However, If you prefer to hold over, the BDC 800 reticle models characteristics Tactical turrets with 1/4 MOA click changes and holdover points out to 800 yards with .308 and 168-grain bullets.

On A locking side focus, generous 4″ there is an eye relief, rugged 1-piece 1″ tube, 40 MOA of interior arrangement, and the included 20 MOA upgraded M308 1-Piece mount executes this the perfect setup for the AR-10 or .308 bolt action firearm.

The added M-308 mount usually fits standard Picatinny-style rails, and with the ample mounting space of the M-308 rifle scope, you can mount the scope to the eye relief for your shooting style. This rifle scope Covered by a limited lifetime warranty.

Use side focus on Nikon M-308:

Nikon M-308 scope has parallax adjustment as the side focus knob. Precisely an appropriate and much-needed thing for long-range scopes. The parallax is movable from 50 yards to eternity and even has a locking feature by pressing the knob in.

Nikon M-308 rifle scopes had a fixed parallax set at 150 meters or 50 yards; Although, with the advance of shooting sports, such an approach was not sufficient anymore.

However, the Nikon M-308 with fixed parallax offered the best resolution only at one distance (50 meters/yards) at which the object was in focus.
At all other distances, the picture was less sharp or even blurry. An even bigger problem with this type of scope was that, whenever shooting at the object, not at the same distance as the scope parallax setting, the shooter had to be very careful about his eye alignment with the optical axis.

However, If the eye is moved away from the optical axis, the reticle on the object will move, which will worsen the accuracy. Since these errors are minor, the fixed parallax option is still considered accurate enough for traditional hunting.

For sport shooting, such small errors lead to poor results. Parallax errors become more pronounced with magnifications higher than 12x, and that means most of the scopes with magnification range under this value need no parallax adjustment.

However, with parallax adjustment, the accuracy of the riflescope is better increased at all distances. The shooter, although, has to adjust the parallax setting before making the first shot. Such scopes usually have AO – Adjustable Objective or SF – Side focus acronym in their name.

With – Side focus in Nikon, parallax is adjusted with a turret rotation on the left side of the main tube. Such an approach may give easy adjustment of the parallax in the prone position, and it is the best solution for situations when one must adjust the parallax frequently.

The Nikon M-308 scope has parallax or Nikon M-308 adjustment as the side focus through the knob. As a sensible and very significant thing for long-range scopes.

The parallax is almost adjustable from 50 yards to infinity, and the other important feature of this scope is a locking feature by pressing the knob in.

The turrets built into the Nikon M-308 are tactical-style turrets. Each of the turrets has a zero-reset characteristic, permitting you to adjust for windage and elevation; however, obtain an object and then go backward to your zero-point settings.

The custom turrets permit rapid changes. The arrangement of commencement on the windage and altitude turret is 1/4 MOA. The turret system on the Nikon M-308 is approved for familiar scopes.

The remarkable feature of the Rapid Action turret system on the M-308 4-16×42 is the automatic zero reset. Other scopes of the same quality do not feature this. Not having disorder around with your rifle to get your zero when in a tree stand is unparalleled.

Why Do You Need to Adjust Parallax or Side focus in scope?

An adjustment to the parallax or side focus is needed because it usually eliminates the
optical illusion during aiming. It generally causes your reticle optic crosshairs to appear fixed on the object anyhow of how you can move your eye.


Adjustable parallax knop in scopes is a perfect thing because it makes aiming more accessible, and it also improves your shooting accuracy. Plenty of rifle brands and scope manufacturing companies usually have added this side focus feature to adjust parallax for the gunner so that shooting accuracy is improved during the hunting process.

For instance, Nikon M-308, Nikon Black, Leupold VX3, or Bushnell Elite 4200 rifle scopes all come with the parallax adjustment characteristic.

The adjustment for side-focused parallax is usually carried out by moving the reticle’s plane to the same distance as the plane’s image. The reticle’s effect is mainly achieved in small increments when you adjust the parallax by a knob.

The point of influence for the bullet changes every time an adjustment is made on the scope, so you should mark which direction to turn on the turret for the necessary correction on the reticle. Check Complete Nikon M-308 Review.

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