Glock Gen3 vs Gen 4 sight alignment difference

[BJXDS]

I have seen this discussed before in reference to Glock's but don't remember it being Gen dependent, maybe I missed something.

I have had to off set my sights to shoot POA/POI on a couple Gen 3's, but on the Gen 4's I set them centered. Same sights Ameriglo Pro idots.

Has anyone else seen this difference between Gen 3 and 4? or is it just a variance with Glock in general and its just a coincidence with the ones I have?

[Nephrology]

Honestly, I think it is probably you. My Gen 4 guns stopped shooting to the left because the smaller grip circumference helped prevent me from "milking" the frame. This was especially pronounced on the Glock 19; not as much the glock 17/35. I don't think either gun is mechanically more prone to shoot to a different windage.

[blues]

Honestly, I think it is probably you. My Gen 4 guns stopped shooting to the left because the smaller grip circumference helped prevent me from "milking" the frame. This was especially pronounced on the Glock 19; not as much the glock 17/35. I don't think either gun is mechanically more prone to shoot to a different windage.

Interesting. Perhaps that is why my Gen 4 G17 has the Trijicon HDs centered while I have my earlier Gen G19 and G26 both drifted to the right.

If it is the case, there's a chance that once I get more time under my belt using a thumbs forward grip I'll be able to drift them back to center. Time will tell.

[Gio]

More often than not, having to offset your rear sights on a glock is caused by having your front sight not perfectly parallel with the slide. On front sights that have a looser fit in the slide, it's easy to twist them almost an imperceptible amount clockwise, which will cause the front plane of the sight to be slightly to the right on the slide. If your front sight is twisted like this, you will have to push your rear sight to the right to compensate. I would estimate that out of the last ~100 or so Glocks that I've looked at where shooters have had to push the rear sight to the right, the front sight being twisted was the cause of 95% of them.

[SAWBONES]

Has anyone else seen this difference between Gen 3 and 4? or is it just a variance with Glock in general and its just a coincidence with the ones I have?

I haven't heard of this, but I don't expect there's really a difference in correspondence between innate POA and POI for different Glock generations as far as barrel and slide fit, yet I seem to have personally noticed such a (tiny) difference between the gen2 & gen3 guns vs. the single gen4 gun I own, for how the rear sight is set.

All the gen2 and gen3 guns (n = 10) I've owned, in 9mm, .40 and .45 Auto, have seemed to require the tiniest left offset of the rear sight for sake of POA/POI correspondence, while the gen4 (n = 1, a G26) rear sight is centered.

This has applied with shooting at different distances, and with a variety of loads, and has been my experience with Glocks extending back nearly thirty years.

I'm left-handed, so if you're right-handed and your rear sight offset on gen3 guns has been to the right, I'd bet it's some sort of grip thing having to do with the fatter grips of earlier generation Glocks compared to gen4.

The "fly in the ointment" of that supposition, though, is that in no case has this sight offset affected precision, that is, once the sights are adjusted "just so", one-hole groups become routine with careful slow fire, which would tend to imply that mechanical function, grip reproducibility and trigger control are consistent.

(It would seem intuitive that if grip position or trigger control issues accounted for the apparent need for sight offset, that there would be some inconsistency in POI.)

[Nephrology]

For what it's worth, the only Glock I own that truly, mechanically shoots to the left is my Gen 4 Glock 17. It sits about 2-3mm left of center in the dovetail. The front sight screw slot is a little bit off center with the bore; this is visible with the naked eye. Also happens to be one of the most accurate Glocks I own, once that is corrected for...

The rest of my Gen 3 and Gen 4 guns have sights that are basically in the center. If they're a little the right it's probably because I figured I'd correct a smidge for my own poor technique...

edit: I also noticed that on my old Gen 3 guns the "left drift" that I once thought was mechanical disappeared during matches. All of my rounds would go POA/POI assuming I didn't pull them entirely off target. That's when I realize I was probably moving too fast through the CoF to be flinching...

[blues]

Well, in my case, Neph, if employing the thumbs forward grip doesn't make any difference down the road vs. my decades old way of doing things...I'll just write it off to mild astigmatism.

[Nephrology]

Well, in my case, Neph, if employing the thumbs forward grip doesn't make any difference down the road vs. my decades old way of doing things...I'll just write it off to mild astigmatism.

The grip may or may not help - what I found was that in matches I didn't have time to overthink the shot and slow move through the trigger press. I would roll right through the break, reset, break of the controlled pair without having the time to agonize over sight picture or whatever else throws me off during slow fire. Less time to anticipate the next shot, as it were.

[blues]

...without having the time to agonize over sight picture or whatever else throws me off during slow fire. Less time to anticipate the next shot, as it were.

I actually prefer shooting to a rhythm such as that vs. standing there trying to get everything perfectly lined up "just so" and ending up expanding the wobble zone in so doing.

Lots of factors to consider for such a "simple" endeavor.

[spinmove_]

My G19Gen4 is zeroed at 25yds with the rear sight ever so slightly to the right. My G17Gen2, it's perfectly centered. It's not a generational thing. It's far more shooter dependent and tolerance/QC dependent.


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[spinmove_]

I don't think your grip technique is going to matter as long as your grip technique isn't pushing your shots one way or the other. If you shoot more accurately/precisely with one grip technique over another then one of those techniques needs to be tweaked so you don't see any difference.


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[blues]

I don't think your grip technique is going to matter as long as your grip technique isn't pushing your shots one way or the other. If you shoot more accurately/precisely with one grip technique over another then one of those techniques needs to be tweaked so you don't see any difference.

I'd probably opt for one of them being dropped in favor of the other...at least that's my plan. Though anything is fair game in a pinch.

[spinmove_]

I'd probably opt for one of them being dropped in favor of the other...at least that's my plan. Though anything is fair game in a pinch.

Whatever ultimately works for you. My point is that your grip technique isn't good if it's pushing your hits off of POA. That whole "don't move the gun while pressing the trigger" thing. ;P


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[BJXDS]

Well, I guess I'll go with, tolerance stacking; me, the grip size, and the front sight being off a bit.

[spinmove_]

Well, I guess I'll go with, tolerance stacking; me, the grip size, and the front sight being off a bit.

Go zero the pistol. If your rear sight is WAY off to one side or another then you're most likely the problem. If it's just a smidge off to one side or another then you're probably not pushing shots. Again, YMMV, could be something else, hard to know for sure on a forum, this is just my experience.


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[M2CattleCo]

More often than not, having to offset your rear sights on a glock is caused by having your front sight not perfectly parallel with the slide. On front sights that have a looser fit in the slide, it's easy to twist them almost an imperceptible amount clockwise, which will cause the front plane of the sight to be slightly to the right on the slide. If your front sight is twisted like this, you will have to push your rear sight to the right to compensate. I would estimate that out of the last ~100 or so Glocks that I've looked at where shooters have had to push the rear sight to the right, the front sight being twisted was the cause of 95% of them.

This is very true and a common oversight when installing new sights.

I install the rear sight first, centered on the slide, then take a straight edge and make sure the front sight is parallel with the rear notch.

None of my Glocks shoot left or right, but I have seen a few that just mechanically shot left.

[EJO]

This is very true and a common oversight when installing new sights.

I install the rear sight first, centered on the slide, then take a straight edge and make sure the front sight is parallel with the rear notch.

None of my Glocks shoot left or right, but I have seen a few that just mechanically shot left.

What is the best way for the average joe to ensure his front sight is true? If the only option is the straight edge route, what would you recommend if it will only be used to make sure sights are aligned? Thanks for your time.

[M2CattleCo]

I use a metal machinists scale, but anything would work.

[EJO]

Thank you! I've ordered one from Amazon and look forward to seeing if any of my front sights are off.

[JonInWA]

More often than not, having to offset your rear sights on a glock is caused by having your front sight not perfectly parallel with the slide. On front sights that have a looser fit in the slide, it's easy to twist them almost an imperceptible amount clockwise, which will cause the front plane of the sight to be slightly to the right on the slide. If your front sight is twisted like this, you will have to push your rear sight to the right to compensate. I would estimate that out of the last ~100 or so Glocks that I've looked at where shooters have had to push the rear sight to the right, the front sight being twisted was the cause of 95% of them.

Gio, any differentiation observed between Gen 3 versus Gen4? I've heard from a very reputable source that Gen4 G22s seem to be especially susceptible to the shooting to the left phenomenon (my sample size of one included).

Best, Jon

[Gio]

Gio, any differentiation observed between Gen 3 versus Gen4? I've heard from a very reputable source that Gen4 G22s seem to be especially susceptible to the shooting to the left phenomenon (my sample size of one included).

Best, Jon

Not that I've noticed. I've actually seen more variation in front sights where some are looser or tighter in the same slide from the same brand (i.e. trijicon HD). Some are so tight fit you can't really twist them off center.

I've seen full time professional agency/department armorers make this mistake, so it's not something that's obvious to most people.

[BJXDS]

The front sight is as straight as I can tell. The gen 3 rear sight is drifted right and the gen4 is centered. I shoot both POA/POI. Strange. But that seems to be the way it is. I guess I will keep shooting both for more comparison. Doesn't really make sense but WTF