How are most sights so accurate on guns, even though they’re a few inches above the barrel?
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A shot is fired and then sights are adjusted so that one shot is in the center of the sight. Now the sights are good for the shot distance that was used to calibrate them. For other distances sights require adjustments. Else you can estimate the bullet drop to longer ranges and do the adjustment with your eyes.
You have to zero them as well. Which is to adjust those sights so they line up with the path of the barrel at a specified distance.
Firing a gun is basically the same concept as throwing a rock; the projectile flies in an arc as gravity pulls it down, not a straight line. Of course firearms are throwing their projectiles much faster so their arcs are flatter than your throwing arm can produce, but the concept is the same.
A sight on a gun though does look in a straight line and there are only two places that straight sightline and arc of the bullet will intersect. The first is where the bullet rises from the barrel above the sightline of the scope or sight; it does this because the barrel is actually pointed slightly upwards compared to the sightline. Then it will intersect again as the bullet falls back down into its line of sight, and that distance is where the scope or sight is “zeroed”. A scope can typically be adjusted to align with intersecting that second crossing point at different distances from the gun, and/or there will be markings on the sight picture indicating where the bullet will strike at different ranges. Knowing how far away a target is is required for a sight to be useful, as just putting the crosshairs on the target isn’t sufficient.
Firing a gun is basically the same concept as throwing a rock; the projectile flies in an arc as gravity pulls it down, not a straight line. Of course firearms are throwing their projectiles much faster so their arcs are flatter than your throwing arm can produce, but the concept is the same.
A sight on a gun though does look in a straight line and there are only two places that straight sightline and arc of the bullet will intersect. The first is where the bullet rises from the barrel above the sightline of the scope or sight; it does this because the barrel is actually pointed slightly upwards compared to the sightline. Then it will intersect again as the bullet falls back down into its line of sight, and that distance is where the scope or sight is “zeroed”. A scope can typically be adjusted to align with intersecting that second crossing point at different distances from the gun, and/or there will be markings on the sight picture indicating where the bullet will strike at different ranges. Knowing how far away a target is is required for a sight to be useful, as just putting the crosshairs on the target isn’t sufficient.
Height above the barrel is a feature. Bullets fly in an arc, just like throwing a ball. If your sight was exactly the height of the barrel, you’d be accurate only at the end of the muzzle and the bullet would fall below your line of sight at every distance beyond that.
In practice, your sight line is straight (we’ll ignore gravity curving light for the distances we’re describing) and your bullet is an arc that starts below the line of sight, rises to meet it, surpasses it, and then falls beneath it. Most sights have the ability to adjust the angle of your straight sight line somewhat, so that your bullet flight arc can be close to your sight line for a greater portion of the bullet’s flight distance.
Height above the barrel is a feature. Bullets fly in an arc, just like throwing a ball. If your sight was exactly the height of the barrel, you’d be accurate only at the end of the muzzle and the bullet would fall below your line of sight at every distance beyond that.
In practice, your sight line is straight (we’ll ignore gravity curving light for the distances we’re describing) and your bullet is an arc that starts below the line of sight, rises to meet it, surpasses it, and then falls beneath it. Most sights have the ability to adjust the angle of your straight sight line somewhat, so that your bullet flight arc can be close to your sight line for a greater portion of the bullet’s flight distance.
Well, they’re actually not. The difference between the height of the barrel of the gun and the sight/optic is called Height-over-bore, and sights and optics have to be regularly adjusted to make sure they’re actually aiming right, this is called sighting. This difference in height means that inherently it’s impossible for any sight or optic to be accurate for all ranges, so usually what’s done is that a few presets are chosen or some optics offer adjustability that remains accurate as long as the gun has been sighted properly at some benchmark range.
Let’s take for example the HK G3, because it has a very intuitive and easy to understand stock iron sight as well as a wide effective range. If you look up a picture of the gun you can see that in the front of the barrel there’s a very typical ring with a small iron vertical pin in the center. In the rear there’s a [rotating drum sight](https://en.wikipedia.org/wiki/File:Heckler_%26_Koch_rotating_drum_sight_pictures.png). The lowest setting has a V shaped notch, which is usually sighted for 100 meters. If you align it as is shown in the picture, and the gun is sighted right, then it should be accurate for 100 meters. But you can also rotate the rear drum sight 90 degrees which then has a small pinhole. There’s three total, each a bit smaller than the other and in a very specific position in the drum sight. These are sighted for 200, 300 and 400m respectively. They’re not very easy to use but it’s a decent system for stock iron sights. It’s up to the shooter to determine the approximate distance from the target, select the closest sight range and make any necessary adjustments. This is where actual gun training comes in, since someone who’s been trained sufficiently with a specific gun and sighting system, can make the necessary adjustments to aim a bit higher or lower intuitively, since they’re familiar with the gun and its ballistics.
In close ranges sights don’t have to be perfect, because it makes little difference in where the bullet will land. As long as your aim is on a target you’ll probably hit it. But at longer ranges these slight differences become more and more pronounced. So basically guns are not really perfectly accurate, there’s obvious limitations to the abilities of an optic to cover all ranges and it’s up to the shooter to make necessary adjustments.
Depends your definition of accuracy. Zeroing the sight for the desired range, and then skills of the shooter are what makes a weapon accurate.
I’ve seen people with a perfectly zeroed M16 fail to qualify.
Depends your definition of accuracy. Zeroing the sight for the desired range, and then skills of the shooter are what makes a weapon accurate.
I’ve seen people with a perfectly zeroed M16 fail to qualify.
Well, they’re actually not. The difference between the height of the barrel of the gun and the sight/optic is called Height-over-bore, and sights and optics have to be regularly adjusted to make sure they’re actually aiming right, this is called sighting. This difference in height means that inherently it’s impossible for any sight or optic to be accurate for all ranges, so usually what’s done is that a few presets are chosen or some optics offer adjustability that remains accurate as long as the gun has been sighted properly at some benchmark range.
Let’s take for example the HK G3, because it has a very intuitive and easy to understand stock iron sight as well as a wide effective range. If you look up a picture of the gun you can see that in the front of the barrel there’s a very typical ring with a small iron vertical pin in the center. In the rear there’s a [rotating drum sight](https://en.wikipedia.org/wiki/File:Heckler_%26_Koch_rotating_drum_sight_pictures.png). The lowest setting has a V shaped notch, which is usually sighted for 100 meters. If you align it as is shown in the picture, and the gun is sighted right, then it should be accurate for 100 meters. But you can also rotate the rear drum sight 90 degrees which then has a small pinhole. There’s three total, each a bit smaller than the other and in a very specific position in the drum sight. These are sighted for 200, 300 and 400m respectively. They’re not very easy to use but it’s a decent system for stock iron sights. It’s up to the shooter to determine the approximate distance from the target, select the closest sight range and make any necessary adjustments. This is where actual gun training comes in, since someone who’s been trained sufficiently with a specific gun and sighting system, can make the necessary adjustments to aim a bit higher or lower intuitively, since they’re familiar with the gun and its ballistics.
In close ranges sights don’t have to be perfect, because it makes little difference in where the bullet will land. As long as your aim is on a target you’ll probably hit it. But at longer ranges these slight differences become more and more pronounced. So basically guns are not really perfectly accurate, there’s obvious limitations to the abilities of an optic to cover all ranges and it’s up to the shooter to make necessary adjustments.
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