How to center rear glock sights?

[Sanch]

Turns out me self installing glock rear sights and eyeballing the zero is not as accurate as I hoped. I've heard calipers can be used to identify the true center of the slide but I can't figure out how to do so and wasn't able to find YouTube videos.

[GJM]

Turns out me self installing glock rear sights and eyeballing the zero is not as accurate as I hoped. I've heard calipers can be used to identify the true center of the slide but I can't figure out how to do so and wasn't able to find YouTube videos.

Isn't it more important where your pistol shoots relative to your rear sight, than whether the rear sight is perfectly centered in the dovetail? Make sure your front sight is straight, though, and correct windage with the rear.

[Pnut]

What sights did you install? Do they slide in the dovetail freely and use a set screw or is there a friction fit?

I guess it’s too late now, but when I replace sights, I’ll draw a center line based in the notch of existing sight. I’d then line up the new sight’s notch to that witness mark. That would be only a baseline though. I’d then take the gun and the my sight pushing tool to the range and get everything zeroed in.

You can find inexpensive sight tools. I have a VISM brand tool that costs about $60.

[1Rangemaster]

GJM is correct, I believe. Solid rear sights in a dovetail are “semi-fixed”; that is they can and should be adjusted for windage by the individual. Shoot a group at lest at 10 yards to start, and adjust. I try and confirm at yardages beyond that, to 25 if possible(and confirm on a steel A/C silhouette at 50).
I don’t think any of my GLOCK sights are perfectly centered…ymmv.

[Leroy Suggs]

First, make sure the front sight is plumb with the slide. Use a straight edge for that. VERY IMPORTANT
Closely eyeball the rear.
Take your adjustment tools with you and shoot at 20-25 yards.
Adjust rear as needed.
Do not worry about rear being dead centered.

[fatdog]

You can use a micrometer to center them in the slide using it's OD and get close, but almost all of mine are the width of a credit card or less off that centering based on the OD of the slide after zero'ing them at the range by putting rounds on target.

[Artemas2]

the simple way with minimal tools, that I used to install dawson adjustables on my 34 was to
measure the slide width, put a pencil mark in the middle (in front of and out a bit from the dovetail)
measure the sight width, put a pencil mark centered on the sight body
adjust until marks touch

That may not be where your sight needs to be for correct POA, but it will get you centered.

[Borderland]

I just eyeball it or use calipers. I take my sight pusher to the range and adjust the rear sigh there. Years ago when I was just starting out a retired Marine sergeant range officer adjusted the sights on my P-220. He took two shots and adjusted with a hammer and punch. Two more shots and another minor adjustment. One ragged hole at 15 yds. after that. Not me, him.

[Sanch]

Isn't it more important where your pistol shoots relative to your rear sight, than whether the rear sight is perfectly centered in the dovetail? Make sure your front sight is straight, though, and correct windage with the rear.

If I was a better shooter, yes. But I have a propensity of shooting left at distance. And in analyzing my guns, I realize most have the sights slightly off.

And yes, they do have the set screw and can free float a bit inside the dovetail. Glocks.

[Sanch]

I just eyeball it or use calipers. I take my sight pusher to the range and adjust the rear sigh there. Years ago when I was just starting out a retired Marine sergeant range officer adjusted the sights on my P-220. He took two shots and adjusted with a hammer and punch. Two more shots and another minor adjustment. One ragged hole at 15 yds. after that. Not me, him.

I have calipers but I'm too stupid to figure out how to use them to center the sights. And it's probably so simple, not a single person has made a YouTube video on it.

there's a dozen ways to use calipers to measure things and I can't figure out how to apply any of them to glock rear sights.

[WobblyPossum]

I have calipers but I'm too stupid to figure out how to use them to center the sights. And it's probably so simple, not a single person has made a YouTube video on it.

there's a dozen ways to use calipers to measure things and I can't figure out how to apply any of them to glock rear sights.

When doing the initial install before shooting and zeroing, I try to come close to centering the sights in the dovetail. To do with with calipers, I install the sight and measure the distance from the left edge of the sight to the left edge of the slide. Then I measure the distance from the right edge of the sight to the right edge of the slide. If the two numbers are the same, then the sight is centered on the slide. If one is larger than the other, you need to drift the sight towards the side with the larger number to close some of that distance. It doesn’t have to be perfect but getting it close to centered at least gives you a starting point for zeroing.

ETA: if you’re asking which part of the caliper makes this the easiest, I use the depth rod which is the part on the opposite end from the jaws. Open and close your caliper jaws and you’ll see a thinner point expand and retract on the opposite end.

[BillSWPA]

When doing the initial install before shooting and zeroing, I try to come close to centering the sights in the dovetail. To do with with calipers, I install the sight and measure the distance from the left edge of the sight to the left edge of the slide. Then I measure the distance from the right edge of the sight to the right edge of the slide. If the two numbers are the same, then the sight is centered on the slide. If one is larger than the other, you need to drift the sight towards the side with the larger number to close some of that distance. It doesn’t have to be perfect but getting it close to centered at least gives you a starting point for zeroing.

ETA: if you’re asking which part of the caliper makes this the easiest, I use the depth rod which is the part on the opposite end from the jaws. Open and close your caliper jaws and you’ll see a thinner point expand and retract on the opposite end.

Using the method described above, and also making sure that the front sight is straight and centered has invariably enabled me to go to the range and confirm zero without making further adjustments.

[Edster]

Ditto WobblyPossum and BillSWPA. I make sure the front sight is mounted straight and securely, then go at the rear with a metal ruler and caliper probe.

If I am confident the sights are mechanically centered, I am very careful before doing any drifting. Shooting off a bag, alternating left/right one-hand, and changing lighting conditions need to produce the same result consistently.

I also make sure to try it with a few rounds of carry ammo. Most of my practice ammo is close enough but not necessarily identical.

More often then not, I find groups left or right are a byproduct of my hands and eyes rather than the sights.

[M2CattleCo]

I eyeball the rear sight and usa a straight edge to align the front sight with the rear notch. The front wants to twist when you tighten it up and that can cause you to shoot left and can also make the front sight look fuzzy.

[LittleLebowski]

The Lebowski method:

- eyeball it in as you whack it with a hammer and punch

- zero at range, with a hammer and punch. The end 😁

[DaBigBR]

The Lebowski method:

- eyeball it in as you whack it with a hammer and punch

- zero at range, with a hammer and punch. The end 😁

I do something similar, although often with a pusher. Works remarkably well.

[hiro]

I have calipers but I'm too stupid to figure out how to use them to center the sights. And it's probably so simple, not a single person has made a YouTube video on it.

there's a dozen ways to use calipers to measure things and I can't figure out how to apply any of them to glock rear sights.

Don't mean to be harsh but honestly, sell the guns and take up knitting.

You'll be able to buy a shit tonne of yarn.

🧶

[ECVMatt]

This guy can talk forever, but at about the 38 minute make he demonstrates the caliper method that I use:


https://www.youtube.com/watch?v=V4G-XcdPVyE

I gets me pretty close to final zero. Always confirm at the range.

I hope this helps,

Matt

[ASH556]

The Lebowski method:

- eyeball it in as you whack it with a hammer and punch

- zero at range, with a hammer and punch. The end 😁

This. I've seen slides cracked with pushers. Doesn't mean it'll always happen, but I've seen it happen first hand. I have several of the Dawson Aluminum punches (I also have steel, brass, and delrin punches I use for other things). A little 0000 steel wool and oil takes the aluminum residue right off.

On a Glock front sight, I put masking tape on my vise jaws, put the slide upside down in the vise and clamp onto the front sight blade. Then adjust left or right as needed until slide lines up with vise jaws.

[Up1911Fan]

I have calipers but I'm too stupid to figure out how to use them to center the sights. And it's probably so simple, not a single person has made a YouTube video on it.

there's a dozen ways to use calipers to measure things and I can't figure out how to apply any of them to glock rear sights.

Don't use the main calipers to measure. Use the depth measuring portion on the end to measure the distance from the edge if the dovetail to the sighton both sides. Adjust until that number is the same for both sides.

That's not what I do, but should help with what you want. I also eyeball it then shoot/adjust/confirm at the range.

[Sig_Fiend]

I wouldn't waste a lot of time on this. Visually center to get in the ballpark. Benchrest it and adjust from there. Loctite when you're done if you have tension screws.

I've had multiple Gen2's where, with visually-centered sights, groupings were off substantially to one side. This was benchrested and confirmed with multiple shooters. One of my Gen2 G17's has the rear sight 70-80% to one side to be dead on. That one is ridiculously worn and has had a hard life. ;) Haven't seen that issue much with Gen3's or newer. For whatever reason, some older ones are real weird like that. Probably something to do with barrel, bore, lug wear, etc.

Point being, you won't know until you shoot it, so don't stress over fractions of a millimeter because it'll probably just change once you shoot for groups.

[RJ]

Being an engineer, naturally I overthink this. I use a sight pusher to get it close, then shoot with carry ammo. Any Windage correction I need I calculate using a spreadsheet to compute % of turn of the 16tpi threaded rod on my pusher, based on how much error I’m seeing at the target.

[JWH]

I also use a hammer and punch. One thing to note is for tight dovetails it can be easier to use light taps with a bigger hammer rather than trying to hit it harder with a small hammer.

[Elwin]

I've had multiple Gen2's where, with visually-centered sights, groupings were off substantially to one side. This was benchrested and confirmed with multiple shooters.

There’s issues like this and then there’s also fit to individuals. I shoot all Walther pistols way, way left if the sight is centered in the slide. All of them. P99s, PPQs of all varieties, PPS M1, PPS M2, all of them, consistently. My friends and family don’t have this problem, and I don’t have this problem with any other guns. When I had four that I carried and trained with, they all had rear sights drifted far to the right.

To the OP, if you don’t shoot well enough to feel comfortable sighting in your pistol, you need to work on that first, and perfect centering of the sight down to the micrometer doesn’t matter. Eyeball the sights to be centered and go shoot and dry fire until you can maintain a consistent group at 10 or 15 yards. Then adjust sights if necessary to move that group on target.

I’m not saying that to be condescending. I’ve been there and I’m sure everyone else here has too.

[UNM1136]

Being an engineer, naturally I overthink this. I use a sight pusher to get it close, then shoot with carry ammo. Any Windage correction I need I calculate using a spreadsheet to compute % of turn of the 16tpi threaded rod on my pusher, based on how much error I’m seeing at the target.

Dude- I literally don't understand anything you posted here....😝🤪🤪


ETA, I use the depth gauge like WobblyPossum to get me in the neighborhood, then take the sight pusher to the range and fiddle.

pat

[FreedomFries]

Easiest tool I have ever used is the Wyoming sight drifter.
If the point of impact is off, I just give the rear sight a whack or two proportionate to how far off it is. I leave an allen key in my range bag to loosen set screws if needed. I have masking tape in my bag to tape holes in targets but I also can put a couple layers down to prevent brass marks on the sight or slide. Beats having to lug around the MGW sight tool when zeroing new sights.

[BWT]

I wouldn't waste a lot of time on this. Visually center to get in the ballpark. Benchrest it and adjust from there. Loctite when you're done if you have tension screws.

I've had multiple Gen2's where, with visually-centered sights, groupings were off substantially to one side. This was benchrested and confirmed with multiple shooters. One of my Gen2 G17's has the rear sight 70-80% to one side to be dead on. That one is ridiculously worn and has had a hard life. ;) Haven't seen that issue much with Gen3's or newer. For whatever reason, some older ones are real weird like that. Probably something to do with barrel, bore, lug wear, etc.

Point being, you won't know until you shoot it, so don't stress over fractions of a millimeter because it'll probably just change once you shoot for groups.

I’d echo this.

Getting it exactly centered is not hugely meaningful if it’s not zero’d. I’d recommend getting a tool to install / shift the rear yourself.