How to Maintain Natural Point of Aim Using a Rifle Scope Bubble Level

Natural Point of Aim (NPA)

NPA is a shot’s projected point of impact based on the alignment of a shooter’s body position and rifle. 

Scope bubble level on scope

It is not a process step that is considered a shooting fundamental, but it is the foundation of the fundamentals

Even without correctly executing any other shooting fundamentals natural point of aim alone will at least get your shot on the paper or within the range of a spotters scope. 

Do not try this at home or at the range, but if you could somehow ignore the fundamentals:  breath wildly, close your eyes, jerk the trigger, and ignore follow through, if your natural point of aim is accurate your shot will still be in the ballpark. 

Shooters often prove the inverse of this to be true by focusing on the five fundamentals without a proper NPA. 

NPA drift is insidious because the visual cues or feel of NPA drift are very subtle.  Further, maintaining NPA is a passive activity. 

Shooters focus on breath control and trigger squeeze because those are activities that require positive action from the shooter and therefore take much of the shooter’s attention. 

If NPA drifts while squeezing the trigger due to some change in the shooter’s body there is no cue to notify the shooter.  Rifle scope bubble levels add a helpful frame of reference to maintain NPA.


Straight Talk About Cant

Cant is measured by degrees of lean from the vertical, either for the rifle or the scope.  

Scope level with the horizon is an important point of reference for NPA because it shows that the shooter is not leaning around the target, that site adjustments will have the expected effect, and it forces the shooter to bring the scope to the eyes, not the eyes down to the rifle. 

Optic Level Large

Rifle scope bubble levels are typically used for shots greater than 500 yards, but that oversimplifies their purpose. 

Canting the rifle barrel has no effect on the point of impact.  Because the bore is in the center of the barrel, and the bullet travels through the bore, canting the rifle barrel just rotates the rifle, but the bullet stays in the middle. 

Canting the scope, however, does affect the point of impact.

Simply put, in order to fire an accurate shot the scope must be level, but scopes can be mounted so that the rile has a degree of cant.

A round scope with a narrow field of view that excludes the horizon and a round target presents a very difficult point of reference for maintaining natural point of aim because there is no reference for level. 

Shooters in the final stage of the firing process will naturally become fixated on the target. 

“Target fixation” is a phrase loaded with negative connotations, but at some point in the firing process target fixation is necessary. 

Even in tactical shooting scenarios with wide field of view optics or iron sights the shooter must aim at the target, focus on one point in space, align the sights and squeeze the trigger. 

It’s important to take the necessary steps prior to those moments when target fixation is necessary.

Setting NPA for the First Shot

Shooters build their position prior to firing the first shot in a series.  NPA on the first shot does not carry the risk of insidious drift because setting an accurate NPA is an inherent part of building a correct position. 

For any shooting position start as if you are building a house, starting with the foundation first. 

Table 2 lists the cornerstones of each shooting position.

The cornerstones are the foundation of each position.  Align these cornerstones as best you think will align to point the rifle at the target. 

THEN start building your position on top of the foundation. 

In prone that means bending the knee, bringing the rifle comb to your cheek, and bring the sights to the shooters eyes. 

As you build your position it is vitally important to bring the sights or scope to your eye, use the scope levels to make sure the scope is aligned, and then look through the scope to check to see if you have built your position in the right place so that the target falls naturally into the center of the scope. 

This step by step approach is necessary prior to each first shot. 

At this point it is likely that you have built a stable position but small adjustments will be needed to point your NPA directly at the target.  

Move each cornerstone of your foundation slightly and all together in order to align the rifle with the target.  

After you adjust the cornerstones check the scope bubble level and bring the scope to your eye, then look through the scope to check if the adjustments brought the target into the center of the reticle. 



Checking the scope bubble level prior to looking through the scope on the first shot accomplishes three things:

  1. A level scope ensures that aimpoint/site adjustments will be aligned. You want one click up to move the point of impact one click up, not one click towards 1 o’clock due to scope cant.
  2. By checking the scope levellers prior to looking through the scope you force yourself to bring the scope to your eyes instead of your eyes to the scope.
  3. You establish the first step in a habit pattern that must be repeated for each follow-on shot.

Maintaining NPA for Follow on Shots

The NPA process is different for follow on shots because the keystones are already in place. 

Natural point of aim must be deliberately monitored during follow on shots because this is when unnoticeable creep starts. 

It’s natural enough for any halfway conscious shooter to establish an accurate NPA prior to the first shot, but what happens over time after a few shots is a slow drifting in NPA that can have a dramatic and unnoticed impact. 

This slow drift is caused by a handful of factors. 

First is muscle fatigue; after a few minutes in any position certain muscles may begin to fatigue or strain. 

These muscles subtly pull the shooter’s bones and move the cornerstones of NPA, causing the NPA to drift off target. 

Second, the shooter may develop a case of the leans around the target due to target fixation. 

This is especially likely in the case of a round target with a round scope and a narrow field of view. 

When a shooter develops the leans the tendency is to rotate or lean around the target. 

The third factor that effects natural point of aim for follow on shots is recoil. 

With a proper NPA the rifle should settle right back on target after recoil, but if the position is imperfect the effects of recoil will cause the body and cornerstones of NPA to drift. 

A feeling of “funny recoil” is a dead giveaway that NPA has drifted from the target, but at that point I tis too late. 

NPA must be reassessed by a methodical process before each shot.

Scope bubble level table 4

A proper habit pattern between shots is necessary for sustained excellent marksmanship over a long course of fire. 

These steps are universal for any pace of fire, any size of rifle, any position, and any distance. 

The degrees of importance of each of these steps and the time available for each step varies based on those factors, but the steps remain universal for any rifle shot.

As previously stated, these steps are universal regardless of the type of shooting. 

If follow on shots are at a target that is in a different location follow through is still back on the target that was just shot, but NPA is established to point at the new target.

A methodical approach to each shot effectively maintains an accurate natural point of aim, which enables shooters to sustain accurate fire. 

Rifle scope level bubbles are a valuable tool because they add a visual point of reference to this process.  

Instilling this four step habit pattern prevents unnoticeable natural point of aim drift.


About the Author:

Will McElwaine is an NRA Certified Rifle Instructor and U.S. Marine Corps Veteran.  He has earned the NRA Rifle Distinguished Expert Award as well as Marine Corps Rifle and Pistol Expert Awards.  He writes informative articles about adventure tourism and firearms and he is still serving in the Marine Corps Reserve.


1 comment
Back to blog

1 comment

we were just going over this with students just the other day . I love that I can explain this in a better way with this write up . thank you so much.

dean comeaux

Leave a comment