Glock and Sig Sight picture

Sawyer.N · April 20, 2017, 07:34 PM

I cant speak much about stock glock sights because I remove them and replace them the moment I get back home with a new one. That being said, I just recently got a 9mm laser bore "sighter".

I have read many places that the proper sight picture for sig sights is to cover up the bulls eye with your front sight dot, and I find that mostly true in practice. Today I confirmed it with my new laser. (it is a very good laser, not some cheap toy) There is a marked difference on where the laser lands in relation to my front sight on my sigp938 and my glock 19. The laser is almost fully covered "behind" my sigs front sight, on my glock it sits half ontop of my front sight (truglo TFO), giving the more "lolipop" or 6oclock sight picture.

Now that I have confirmed that for myself, my question is why. Why do some pistols require a 6oclock hold, rendering the POI just ontop of the front sight blade? Why do others land on the bulls eye fully behind, or fully covered by the front sight tip.

Does it have to do with the manufacturing of the sights, or with the production of the slide/barrel? Ballistics? Idk. very curious as to what light you all may be able to shed on this.

I Know for a fact that If I fire a round at a distance of 1 inch away from a target with my sights on the X, its going to hit well underneath it, but at distance, it hits "at the top" of my front sight blade.

TunnelRat · April 20, 2017, 07:37 PM

Quote:

Why do some pistols require a 12oclock hold, rendering the POI just ontop of the front sight blade?

Maybe I'm not reading correctly, but wouldn't this be a 6 o'clock hold? A 12 o'clock hold would be the POI is below the front dot so you have to hold at 12 o'clock on the target.

AxlMyk · April 20, 2017, 07:52 PM

Quote:

I Know for a fact that If I fire a round at a distance of 1 inch away from a target with my sights on the X, its going to hit well underneath it, but at distance, it hits "at the top" of my front sight blade.

Well, consider that a moment.
When you shoot 1" away, the barrel is lower than the sight. So the bullet will hit lower than the sight is.
At distance, the bullet is still rising until a certain point in its ballistics track, whereupon it begins to fall.

Sawyer.N · April 20, 2017, 08:03 PM

Quote:

Maybe I'm not reading correctly, but wouldn't this be a 6 o'clock hold? A 12 o'clock hold would be the POI is below the front dot so you have to hold at 12 o'clock on the target.

You are correct, my bad on the typo going to edit now

Sawyer.N · April 20, 2017, 08:06 PM

Quote:

When you shoot 1" away, the barrel is lower than the sight. So the bullet will hit lower than the sight is.
At distance, the bullet is still rising until a certain point in its ballistics track, whereupon it begins to fall.

This is the information I think I am looking for. So a bullet rises up word how ever much in its "ballistic track"? Dont judge me for not knowing, or being misinformed, but I thought that the bullet will travel fairly strait due to being fired down a barrel with riffling twist. This is not true? It will rise through its flight?

pblanc · April 20, 2017, 08:25 PM

The sight line on a firearm is not parallel with the bore axis. If it was, the firearm would have a POI below POA at all ranges. That is because the sights are situated a significant distance above the bore axis, and all projectiles start to drop, due to the effect of gravity, as soon as the projectile leaves the end of the barrel.

So the sight line actually intersects the line of the bore axis at some point. The point at which it intersects is determined by the relative heights of the front and rear sights. So the sight picture on a pistol with dovetailed sights can easily be altered by changing the height of the front sight, rear sight, or both. Making the rear sight higher, or the front sight lower, will raise the groups at any given range. If you want your shots to group lower, lower the rear sight, raise the front sight, or both.

Since the sight line intersects the line of the bore axis there will generally be two distances for which the firearm is "sighted in". The trajectory of the projectile is not a straight line, of course, but follows a curved path due to gravity. How much a projectile drops for any given distance traveled is determined by its velocity. Faster projectiles shoot flatter because they travel farther for any given degree that they are affected by gravity. Projectile velocity is determined by muzzle velocity and the degree to which air resistance slows them down. Projectiles that are more streamlined have less drag (higher ballistic coefficient) and do not slow down as quickly.

So when the projectile leaves the barrel, it starts along the line of the bore axis but immediately starts to drop. As it leaves the barrel, the projectile path is below the sight line. At some point it intersects the sight line. It then usually travels above the sight line but due to its drop, eventually crosses the sight line a second time. It is possible to sight a weapon so that the path of the projectile just climbs up to the sight line at the apex of its curved path and then immediately starts to drop. In that case, the weapon will be sighted in for that distance only, and will shoot below POA for every other range.

So how a firearm is sighted in is a somewhat complicated matter that depends on the projectile fired, the muzzle velocity (which can also depend on barrel length), the height above the bore axis the sight line is situated, and the choice of sights. Different manufacturers seem to have different preferences for sight pictures and slightly different ranges selected to sight in their weapons, and so select different sight heights.

Sawyer.N · April 20, 2017, 08:34 PM

pblanc

Thanks so much for taking the time to type up all that information, as complicated as it sounds I'm having one of those DUH moments. Really appreciate it, and it all makes plenty of sense *deletes thread*

dgludwig · April 25, 2017, 04:30 PM

One of the reasons many serious target shooting competitors use the "6 o'clock hold" is because the sight alignment definition is much easier to discern when the sights are contrasted against a white background as opposed to "merging" with a black backdrop. Properly sighted-in, bullets fired using a 6 o'clock hold will, of course, hit the x-ring if the shooter does his job.

Jim Watson · April 25, 2017, 04:49 PM

Quote:

Why do some pistols require a 6oclock hold, rendering the POI just ontop of the front sight blade? Why do others land on the bulls eye fully behind, or fully covered by the front sight tip.

Because that is what the respective manufacturers think their customers want.
Ballistics don't really come into it, the sights are designed and installed to shoot a particular way.

Actually there are three standard sight pictures.
1. A true 6 o'clock hold has the top of the front sight tangent to the bottom of a circular bullseye and the shots hit in the center of the bullseye. Some would say the gun is shooting "high" but it is regulated to allow a precisely repeatable sight picture for that one target at that one range.

2. A center hold has the top of the front sight in the center of the target and the shots hit in the center of the target. It can be reasonably precise and is considered more versatile than the 6 o'clock hold because the Point of Aim and the Point of Impact coincide or nearly so with little variation over normal pistol ranges.

3. The SIG setup is sometimes known as "drive the dot." It has the spot on the front sight in the center of the target and the shots hit the center. It is a fast and intuitive sight picture, easily instructed, but less precise than 6 o'clock or center.

There are some nonstandard sight pictures for specific applications or personal preference.
I like my bullet holes to all be visible above the top of the front sight. Below a true center hold by the radius of the group. It serves me well for my main event, IDPA competition.

A PPC shooter will use a head or neck hold on the humanoid B27 target. He can get a sight picture nearly as good as a 6 o'clock hold on a bullseye, but the shots are landing in the ten ring located in the "torso." The gun is shooting very low by most standards, but it works well in this one application.

I knew one guy who prided his small object marksmanship, an experienced plinker shooting cans, empty shotgun shells, and small varmints. He claimed to have adjusted his sights for a point of impact at the top left corner of his front sight.

The U notch and bead sight set are having a renaissance, displacing the 1909 Patridge patent square sights for some users.

DaleA · April 25, 2017, 06:53 PM

Quote:

There are some nonstandard sight pictures for specific applications or personal preference.

Here's another one. At one time I shot Smallbore (saying smallbore is sooooooo much cooler than saying .22) rifle indoors and the distance was 50 feet. That's 50 feet, not yards. The hot setup if you were shooting in the divisions that allowed scopes was to put a 20X Unertl scope on your .22 rifle. Yep, 20x. When shooting International targets there isn't a center ring like on NRA targets, there is a center dot. Just kind of a period. One of our coaches found it irritating that the cross hairs on his scope covered too much of the dot so he adjusted his scope so the dot just to the right and above the crosshairs intersection point. He liked it that way.

I'm a big fan of adjustable sights on guns except for maybe self-defense handguns where I see the need to keep things simple and rugged.

Jim Watson · April 25, 2017, 07:15 PM

And benchrest shooters will usually have an offset aiming point so their shots don't chew it up.

Sawyer.N · April 26, 2017, 12:20 PM

Jim Watson,

Thanks for sharing all that. It explains so much for me. And you are right about the more intuitive center hold, or the "drive the dot hold". My acquisition and natural POA seems to come quicker with my firearms of this sight picture, and my slow fire groups are typically more precise with my glock, with the 6 oclock hold.

April 20, 2017, 07:34 PM	#1
Sawyer.N Member Join Date: January 25, 2017 Location: Washington state Posts: 86	Glock and Sig Sight picture I cant speak much about stock glock sights because I remove them and replace them the moment I get back home with a new one. That being said, I just recently got a 9mm laser bore "sighter". I have read many places that the proper sight picture for sig sights is to cover up the bulls eye with your front sight dot, and I find that mostly true in practice. Today I confirmed it with my new laser. (it is a very good laser, not some cheap toy) There is a marked difference on where the laser lands in relation to my front sight on my sigp938 and my glock 19. The laser is almost fully covered "behind" my sigs front sight, on my glock it sits half ontop of my front sight (truglo TFO), giving the more "lolipop" or 6oclock sight picture. Now that I have confirmed that for myself, my question is why. Why do some pistols require a 6oclock hold, rendering the POI just ontop of the front sight blade? Why do others land on the bulls eye fully behind, or fully covered by the front sight tip. Does it have to do with the manufacturing of the sights, or with the production of the slide/barrel? Ballistics? Idk. very curious as to what light you all may be able to shed on this. I Know for a fact that If I fire a round at a distance of 1 inch away from a target with my sights on the X, its going to hit well underneath it, but at distance, it hits "at the top" of my front sight blade. Last edited by Sawyer.N; April 20, 2017 at 08:04 PM.

April 20, 2017, 08:25 PM	#6
pblanc Senior Member Join Date: March 23, 2008 Location: Indiana Posts: 697	The sight line on a firearm is not parallel with the bore axis. If it was, the firearm would have a POI below POA at all ranges. That is because the sights are situated a significant distance above the bore axis, and all projectiles start to drop, due to the effect of gravity, as soon as the projectile leaves the end of the barrel. So the sight line actually intersects the line of the bore axis at some point. The point at which it intersects is determined by the relative heights of the front and rear sights. So the sight picture on a pistol with dovetailed sights can easily be altered by changing the height of the front sight, rear sight, or both. Making the rear sight higher, or the front sight lower, will raise the groups at any given range. If you want your shots to group lower, lower the rear sight, raise the front sight, or both. Since the sight line intersects the line of the bore axis there will generally be two distances for which the firearm is "sighted in". The trajectory of the projectile is not a straight line, of course, but follows a curved path due to gravity. How much a projectile drops for any given distance traveled is determined by its velocity. Faster projectiles shoot flatter because they travel farther for any given degree that they are affected by gravity. Projectile velocity is determined by muzzle velocity and the degree to which air resistance slows them down. Projectiles that are more streamlined have less drag (higher ballistic coefficient) and do not slow down as quickly. So when the projectile leaves the barrel, it starts along the line of the bore axis but immediately starts to drop. As it leaves the barrel, the projectile path is below the sight line. At some point it intersects the sight line. It then usually travels above the sight line but due to its drop, eventually crosses the sight line a second time. It is possible to sight a weapon so that the path of the projectile just climbs up to the sight line at the apex of its curved path and then immediately starts to drop. In that case, the weapon will be sighted in for that distance only, and will shoot below POA for every other range. So how a firearm is sighted in is a somewhat complicated matter that depends on the projectile fired, the muzzle velocity (which can also depend on barrel length), the height above the bore axis the sight line is situated, and the choice of sights. Different manufacturers seem to have different preferences for sight pictures and slightly different ranges selected to sight in their weapons, and so select different sight heights. Last edited by pblanc; April 20, 2017 at 08:34 PM.

April 25, 2017, 04:30 PM	#8
dgludwig Senior Member Join Date: February 12, 2005 Location: North central Ohio Posts: 7,486	One of the reasons many serious target shooting competitors use the "6 o'clock hold" is because the sight alignment definition is much easier to discern when the sights are contrasted against a white background as opposed to "merging" with a black backdrop. Properly sighted-in, bullets fired using a 6 o'clock hold will, of course, hit the x-ring if the shooter does his job. __________________ ONLY AN ARMED PEOPLE CAN BE TRULY FREE ; ONLY AN UNARMED PEOPLE CAN EVER BE ENSLAVED ...Aristotle NRA Benefactor Life Member

April 20, 2017, 08:34 PM	#7
Sawyer.N Member Join Date: January 25, 2017 Location: Washington state Posts: 86	pblanc Thanks so much for taking the time to type up all that information, as complicated as it sounds I'm having one of those DUH moments. Really appreciate it, and it all makes plenty of sense deletes thread

April 25, 2017, 07:15 PM	#11
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,541	And benchrest shooters will usually have an offset aiming point so their shots don't chew it up.

April 26, 2017, 12:20 PM	#12
Sawyer.N Member Join Date: January 25, 2017 Location: Washington state Posts: 86	Jim Watson, Thanks for sharing all that. It explains so much for me. And you are right about the more intuitive center hold, or the "drive the dot hold". My acquisition and natural POA seems to come quicker with my firearms of this sight picture, and my slow fire groups are typically more precise with my glock, with the 6 oclock hold.