What Is Point of Impact, and What Determines It?
Kat Ainsworth Stevens
If you spend much time at the range, you’re likely to hear the terms point of aim and point of impact. Maybe you’re wondering what those phrases mean and whether they affect you at all as a shooter, or perhaps you’re curious how point of impact changes (or doesn’t change at all) when shooting suppressed. We’re here to answer those questions and explain why an awareness of point of impact is a good thing for all gun owners.
What is Point of Impact?
When you’re shooting, point of impact refers to the location at which the bullets strikes the target. Your point of impact doesn’t always match point of aim which is an important concept to familiarize yourself with to become a better shot. This becomes clear when shooting at longer distances and learning about things like holdover. You’re not aiming precisely where you intend to hit, you’re aiming at the spot necessary for your shot to impact in the correct location based on various factors.
How Point of Impact Is Determined
Point of impact is determined by various factors such as point of aim, distance, and wind. And for point of impact to be where you need it to be, your gun needs to be zeroed. More on that later.
Ballistics and trajectory come into play with point of impact. For example, if your gun is zeroed at 100 yards but you’re close to a target and aim at it the same way you would at greater distances, you might be surprised to find your shot impacts the target lower than anticipated. That’s because a close-range shot involves a bullet that hasn’t gone through its full trajectory, so if you’re close enough, it hasn’t risen like it will at further distances.
If you’re using optics, you’ll need to zero the optic so your point of aim works with point of impact. An optic that isn’t zeroed can result in point of impact being all over the place, especially at longer distances. You can’t swap an optic from gun to gun without zeroing it every time and expect accurate hits.
Using iron sights requires sighting in to both accustom yourself to point of aim and how it relates to point of impact and, in the case of adjustable iron sights, to allow you to adjust elevation and/or windage as needed for more accurate hits on target.
Why Suppressors Don't Change Point of Impact
Suppressors don’t affect point of impact in the way many people believe they do. In fact, if your suppressor is precisely aligned with your barrel, you’re unlikely to notice a difference at all. Similarly, larger bore firearms tend not to experience a point of impact shift like smaller ones might. But is it the suppressor that really affects it or something else entirely?
Adding weight and length to your gun’s barrel can shift point of impact, but it’s not because the suppressor itself that literally changes point of impact. That means once you have your gun zeroed or sighted in with a suppressor, you’ll be right on target just like you are without a suppressor. However, the additional length and use of a device alter the barrel harmonics of your firearm. This means when you haven’t zeroed your gun and try to aim and shoot like you would without the suppressor, your results might not be quite the same. The harmonics changed, and you need to both zero the gun accordingly and get used to the difference in length and weight.
Generally speaking, adding a suppressor and then zeroing your gun results in greater accuracy than you experienced prior to the addition of the suppressor. This is due to a few things including the way a suppressor can somewhat reduce felt recoil.
What is Point of Impact Shift?
This refers to the shift in point of impact many shooters notice when adding a suppressor to their firearm. That shift might be real or perceived and certainly varies by gun, suppressor, and mounting system. Lighter, thinner barrels generally see a point of impact shift. Similarly, heavier suppressors often cause more of a shift than lighter ones. And, point of impact might simply shift when the suppressor is new and the shooter has yet to properly zero their firearm or it might change from shot to shot. The latter problem often stems from the type of mounting system used or is caused by a suppressor walking itself loose on the barrel of the gun. These are signs to watch for to ensure the suppressor is securely attached to the barrel of the gun.
Guess what can cause point of impact shift that has nothing to do with the suppressor itself? Improperly threaded barrels. If the barrel threads aren’t done precisely correctly, it means the suppressor might not be able to mount precisely to the gun, resulting in a shift. Shifts don’t necessarily have anything to do with the suppressor itself. In addition, you yourself can cause point of impact shift by failing to account for the extra weight and length while shooting.
When it comes right down to it, a suppressor on a zeroed firearm will usually deliver more precise results on target than the shooter was getting before adding the suppressor.
Kat Ainsworth Stevens
