What does it mean to zero a pistol with fixed iron sights?

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WaltherPPQ

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I'm looking at a semi-automatic pistol with fixed sights which reviewers are saying shoots very tight groups but shoots low. The manual states that the pistol is zeroed for 25 metres. And, people are saying that that is why the pistol shoots low at closer ranges such as 7 and 10 metres.

I understand how a pistol with an adjustable rear sight can be used to zero a pistol both for range and windage. Also, even a fixed rear sight can be adjusted for windage by moving it in its dovetail.

I don't follow how anyone--the factory included--can adjust a pistol, i.e. zero it, for range. What does it mean, the pistol has been zeroed for 25 metres at the factory when both the front and rear sights are fixed?

Thanks.
 
Zeroed range with fixed iron sights mean that the sight alignment vertically results in POI and POA being the same at set distance. However this is only true for the exact load used by the factory and approximately true for close loads.

Most military rifles of the early 20th century also had a fixed battle sight “zeroed” at some range but this was more accurate as every rifle used the same load

It’s not that factory has zeroed the sights, it’s that they designed them so that at 25 yards and invisible line extending out of the bore (more correctly trajectory of the bullet) and a correctly aligned sight picture intersect at 25 yards
 
In reality, the gun can only zeroed by the owner, with his ammo.

I am a good shot. So is my buddy. At 20 yards we shoot the same elevation with each other's pistols, but there is a 4" shift left or right. I suspect it is because of the way we hold and squeeze the grips.

I find S&W MP pistols ( I have 4 of them) all shoot too high (or too low - I forget). So I test shoot it and order a new front sight of the correct height. I do the same with Glocks, because I prefer a narrower fibre optic front sight.
 
When I installed new sights on a 1911 that required milling the slide I did a bunch of shooting and some math to figure out how high the rear sight needed to be in relation to the front sight, and then had the slide dovetails machined accordingly. You can also buy different height front sights, some pistols even come with several different ones.
Kristian
 
http ://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=40556acd


Drag Function: G1
Ballistic Coefficient: 0.48
Bullet Weight: 115 gr
Initial Velocity: 2800 fps
Sight Height : 1.5 in
Shooting Angle: 0° Wind Speed: 0 mph
Wind Angle: 0°
Zero Range: 25 yd
Chart Range: 50 yd
Maximum Range: 5994 yd
Step Size: 25 yd
International Standard Atmosphere
Altitude: Sea Level (0 ft)
Barometric Pressure: 29.92 Hg
Temperature: 59° F
Relative Humidity: 50%
Speed of Sound: 1116 fps

Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.00 0.00 0.00 0.00 2002 2800
25 -0.01 0.03 0.01 0.00 0.00 0.00 0.03 1934 2752
50 1.18 -2.25 -0.66 0.00 0.00 0.00 0.05 1868 2704
 
1ABNDT said:
http ://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=40556acd


Drag Function: G1
Ballistic Coefficient: 0.48
Bullet Weight: 115 gr
Initial Velocity: 2800 fps
Sight Height : 1.5 in
Shooting Angle: 0° Wind Speed: 0 mph
Wind Angle: 0°
Zero Range: 25 yd
Chart Range: 50 yd
Maximum Range: 5994 yd
Step Size: 25 yd
International Standard Atmosphere
Altitude: Sea Level (0 ft)
Barometric Pressure: 29.92 Hg
Temperature: 59° F
Relative Humidity: 50%
Speed of Sound: 1116 fps
Click to expand...

I don't want to be anywhere near you when you push a 115gr 9mm pill at 2800fps out of a pistol!

OP, the good news is a low shooting pistol is easily fixed; file the front sight as required to raise the point of impact. Go slow.
 
TT1900 said:
I don't want to be anywhere near you when you push a 115gr 9mm pill at 2800fps out of a pistol!

OP, the good news is a low shooting pistol is easily fixed; file the front sight as required to raise the point of impact. Go slow.
Click to expand...

Lol, my Bad.
 
http ://www.shooterscalculator.com/ballistic-trajectory-chart.php?t=c480bbbb

Drag Function: G1
Ballistic Coefficient: 0.48
Bullet Weight: 115 gr
Initial Velocity: 1180 fps
Sight Height : 1.5 in
Shooting Angle: 0° Wind Speed: 0 mph
Wind Angle: 0°
Zero Range: 25 yd
Chart Range: 50 yd
Maximum Range: 4936 yd
Step Size: 25 yd
International Standard Atmosphere
Altitude: Sea Level (0 ft)
Barometric Pressure: 29.92 Hg
Temperature: 59° F
Relative Humidity: 50%
Speed of Sound: 1116 fps

Range Elevation Elevation Elevation Windage Windage Windage Time Energy Vel[x+y]
(yd) (in) (MOA) (MIL) (in) (MOA) (MIL) (s) (ft.lbf) (ft/s)
0 -1.50 0.00 0.00 0.00 0.00 0.00 0.00 356 1180
25 0.00 0.02 0.01 0.00 0.00 0.00 0.06 343 1160
50 -0.14 0.27 0.08 0.00 0.00 0.00 0.13 332 1141
 
What does it mean to zero a pistol with fixed iron sights?

Assuming the sights are centered left-right properly for your eyes, you only have to worry about the elevation.

For me, it means knowing what your Point of Impact will be, for your preferred sight picture or Point of Aim. You have to shoot at different relevant ranges, say 5 meters, 10, 15, 20 and 25 meters. You may have to hold-under, hold-over, or hold-center at the different ranges. Only you can figure that out by shooting and being familiar with your pistol. Hopefully you shoot only one load, or your POI may vary with different loads. POI may vary 4 inches vertically from 5 to 25 meters, and that's still considered pretty good.
 
easyrider604 said:
What does it mean to zero a pistol with fixed iron sights?

Assuming the sights are centered left-right properly for your eyes, you only have to worry about the elevation.

For me, it means knowing what your Point of Impact will be, for your preferred sight picture or Point of Aim. You have to shoot at different relevant ranges, say 5 meters, 10, 15, 20 and 25 meters. You may have to hold-under, hold-over, or hold-center at the different ranges. Only you can figure that out by shooting and being familiar with your pistol. Hopefully you shoot only one load, or your POI may vary with different loads. POI may vary 4 inches vertically from 5 to 25 meters, and that's still considered pretty good.
Click to expand...
:agree:

I shoot PPC recreationaly, (not a real serious competitor). I use 4 different guns because I like shooting them. Two have sights that are adjustable for windage and elevation; the other two fixed sights. The two that are adjustable, my .45 1911 and my GP100 are zeroed to 120 yards, my Nork NZ85 9mm shoots the same zero elevation wise with 124 gr light loads, but needed to be drifted for windage. My Jericho .40 full size, steel pistol also needed a windage adjustment, but the sight configuration on it shoots about 8" low at 20 yards. One of the more experienced shooters told me that this is normal for those pistols (he called it a neck-hold); in battle conditions you aim so the target's "head" is sitting on top of the front sight, and the bullets will hit center of body mass. It works well with that pistol.

If you are only shooting 1 pistol, get a sand bag to rest on and figure out where it is actually shooting (use lots of ammo to confirm). Adjust your windage accordingly. Then shoot free hand, and adjust your hold to give you the elevation that you desire, then practice (lots of dry fire) until you can hold your point of aim to "zero" your windage... This could take a few hundred, to a couple thousand rounds. It eventually becomes like breathing. Time well spent, and a lot of fun!
B_27_PR.jpg
 
Fixed sights are cheap to manufacture, don't break (usually). For police and military work, as long as it hits close, that's good enough. For civvies like us that like to hit bulls, that means either switching to adjustable sights, or learning to compensate for the sights by using a hold-over (aiming a few inches higher or lower, depending on distance to target), or filing down or replacing the front sight to get point of impact to match point of aim for the distance you'll shoot the most, with the ammo you'll shoot the most. For example, if you're shooting IPSC, you could be reloading less powerful ammo, and most of your distances would be in the 5-15m range.

One final thing to check, is to have one or more other people shoot that gun. I've had folks say their gun is shooting "off", but when someone else tries it, it's just fine. Something about the shooter's grip, sight picture, or something that can be troubleshot.
 
WaltherPPQ said:
I'm looking at a semi-automatic pistol with fixed sights which reviewers are saying shoots very tight groups but shoots low. The manual states that the pistol is zeroed for 25 metres. And, people are saying that that is why the pistol shoots low at closer ranges such as 7 and 10 metres.

I understand how a pistol with an adjustable rear sight can be used to zero a pistol both for range and windage. Also, even a fixed rear sight can be adjusted for windage by moving it in its dovetail.

I don't follow how anyone--the factory included--can adjust a pistol, i.e. zero it, for range. What does it mean, the pistol has been zeroed for 25 metres at the factory when both the front and rear sights are fixed?

Thanks.
Click to expand...

I guess the best way to explain this IMO, is that based on the ammo (so lets say 147gr) and using 25m, the pistol will/should shoot usually plus or minus 4", or least in my experience that's the standard. Most pistols are sighted for POA & POI, so what that "usually" means is that using the sights, most shooters generally "split" the target using there POA. Ammo can make a huge difference, for instance if the pistol is zeroed with 147gr and the shooter is using 115gr or 124gr in the case of 9mm, they may? have some noticeable differences?. Changing the sights is one way to compensate for this.
 
I like POA—POI. Some sights are set up 6o’clock hold. That gives you a higher POI than POA at a defined difference. Apparently this is a target set up that allows you a clear view of a precise aiming point(edge of bullseye) while the impact point is centered (middle of bullseye) I’m not a fan of this set up
 
SLANTO said:
I like POA—POI. Some sights are set up 6o’clock hold. That gives you a higher POI than POA at a defined difference. Apparently this is a target set up that allows you a clear view of a precise aiming point(edge of bullseye) while the impact point is centered (middle of bullseye) I’m not a fan of this set up
Click to expand...

I'm with you on that. I hate 6 o'clock hold. If I shot something like PPC or Olympic type pistol I would likely use it. I want my shots to be directly under the fibre optic rod of my front sight. So in a perfect shot world I wouldn't be able to see my hit
 
There's two ways to alter elevation on a fixed sights gun.

First is altering your ammo. Either buying ammo with bullet weights that hit at the proper elevation to match the sight's POA. Lighter or faster bullets tend to shoot lower, Heavier or slower tend to shoot higher. Often lighter is also faster and heavier is also slower for given power charges.

I found that revolvers follow this light bullet/heavy bullet and slower/faster rule more strongly than semi autos. But semis do act the same even if the change is less. Case in point is a revolver I've got in .357Mag at 12 yards adjusted for .38Spl to be spot on will shoot the same weight bullet in .357Mag almost 3 inches low. When trying some 9mm loads in 115, 124 and 147gns at different power levels and chronoing I found a roughly 2" difference at 12 yards.

Anyway... to some extent you can tune the POI to the POA by testing and using the right ammo. In WaltherPPQ's case where the gun is shooting a bit low at 10 yards I'd try 124gn if you're currently using 115. Or try some 147 if the 124 isn't hitting high enough.

The other option is to recognize that ANY sight is adjustable with the right tool. For "adjustable" sights that is a small screwdriver or allen key. For one piece sights the proper tool can be a small fine metal file and a few strokes to slightly reduce the height of the front sight. If you do this a little goes a long way For 2 inches at 10 yards you'll only need to remove a very small amount. Roughly the thickness of a business card in fact.

To some extent the final height will also depend on the shooter in terms of how tight they grip the gun and how heavy their arm is. So the shooter should be the one that does the final testing. And hopefully they are a good enough shot that the small changes are not buried in a bad flinch or the shakes from too much strong coffee or just bad nerves. Not much point in worrying about a 1.5" difference in POI if the group at the desired distance is 7 x 5 inches....


If you're no good at metal work of this sort then either live with a touch of "Kentucky elevation" or pay for a proper smith to do the work.
 
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