Rear iron sight drifting on RDS handguns?

[Chriscanbreach]

As we transition more officers to RDS on their duty Glocks I’ve noticed the rear irons are prone to drifting. The fist time I noticed it about a year ago I just assumed I had bumped it in my holster on duty sometime.

During high round count days my ameriglow all black suppressor sights have drifted noticeably left. During a 600ish round class on Monday one of my teammates and mine had done the same. Conversely one officer had Dawson’s mounted in front of his Delta point and they had drifted right.

Does the added mass of suppressor sights higher up allow them to rock their way out? Does the heating of the slide have something to do with it? Or is it as simple as poor fit?
Either way, we are looking at red locktite and using a punch to fix the sight in place. This was recommended by a CZ factory Smithy in our class.
My 19 was done by ATEI and uses the factory rear dovetail. The second one was on an MOS 17 and the Delta was on a milled Sig done by a local shop.

We can’t be the only ones who’ve noticed this happening. If you have a fix or recommendation let the group know.
So far hitting the corners with a punch has worked.

 

[David Mayeur]

The question is...

Who installed them?

 

[Chriscanbreach]

Mine were installed by ATEI. The dents in the rear sight were put there by me beating it back into place with a punch on the range. Cosmetics are of zero concern to me.

 

[Chriscanbreach]

Like I said I’ve only noticed it under heavier firing schedule / 600+ rounds in a day.
Seven of us were doing a private tune up with Elias Frangoulis and the sites had drifted slightly by the lunch break. 300 or so rounds in a couple hours.
I ask the question because while I don’t notice the sights at all while shooting were transitioning officers who are new to RDS and I don’t want them freaking out thinking their dot has lost zero when the irons are what shifts.

 

[Oak City Tactics]

Shouldn’t we see this with other tall sights? My Dawson MOS sights are not much taller than my Dawson adjustables and certainly the adjustable has more mass. I’ve not seen it with my Trijicon’s though either. I’ve only ever had suppressor height sights on an MP Core and two Glock MOS’s. The set screw should prevent any movement with the Dawson’s. Blue loctite is your friend on the set screw. Red may be your friend on the reaper dovetail.

 

[Chriscanbreach]

There is no set screw on the ameriglows and I’m curious if we hit a bad batch that’s missing some on the QC. If anyone else has noticed it let me know. Thanks for the input.

 

[Yondering]

I gotta think you've just got a poor fit issue, most likely an undersized rear sight but could be a loose dovetail. I've been shooting RMR-equipped Glocks since 2012, averaging 1,000 rounds per month for the last few years, and have never seen one of my suppressor sights drift.

I'd try a new rear sight first, but if that doesn't fix it have a gunsmith peen down the top edges of the dovetail or install the rear sight with a shim. Loctite can help too.

 

[David Mayeur]

Mine were installed by ATEI. The dents in the rear sight were put there by me beating it back into place with a punch on the range. Cosmetics are of zero concern to me.

As soon as it drifted, you should have stopped. Hammering it back into place was a bad idea. It will drift again.

Glock dovetails are not perfect. I have a set of adjustable Dawson Precision sights that fit well in a Glock 17 and terrible in my Glock 17L. Buy a new rear sight and have it professionally installed if you do not feel capable of doing so yourself.

 

[Chriscanbreach]

Yondering, a poor fitting batch is about what we’ve come to the conclusion on. We’ve already peened the rear as shown in the picture and will keep shooting them to see what happens. 1k round weeks are about average and it was only noticeable after this particular class.
Going forward we may just require sights with a set screw.

David, I’m new here so not sure if I should take your comments as condescending or constructive with misplaced preaching. We all have different experiences and I realize most officers are woefully under trained let alone competent with their weapons and that is just a sad fact.
My original question was has anyone else noticed this and what could cause it. It didn’t need the response of
“The question is ...”

I think the ... is what annoyed me most. Just ask who installed them. And don’t I’m not a gun smith or didn’t have one peen and set my sight while on the range.

Thank you

 

[David Mayeur]

I apologize if it sounded condescending. That wasn't the goal.

The reason I asked who installed it was because it gives me an idea of HOW it was installed. Some folks use sight pushers without fitting the sight, some use a hammer and punch to force the sight into place, while others may use a small hammer, punch, and a file to fit the sight perfectly.

Since ATEi were the ones who installed it, I have to assume it was installed properly and it's due to a sight that was out of spec from the factory or an oversized dovetail from Glock. Sights are cheap (relatively speaking), I would acquire a new rear sight and have it installed. If the problem persists, I would contact ATEi and talk to them about the issue.

 

[user12358]

Since ATEi were the ones who installed it, I have to assume it was installed properly and it's due to a sight that was out of spec from the factory or an oversized dovetail from Glock.

Why would you assume it was properly installed if they weren't able to tell that that the sight was not forming a proper press fit on installation and appear to have not used a locking compound? There is simply no way to miss the sight or dovetail having an incorrect dimension if the sight is being properly installed unless they simply didn't care or don't know.

 

[David Mayeur]

Why would you assume it was properly installed if they weren't able to tell that that the sight was not forming a proper press fit on installation and appear to have not used a locking compound? There is simply no way to miss the sight or dovetail having an incorrect dimension if the sight is being properly installed unless they simply didn't care or don't know.

I would assume so, because that company happens to do quality work. Does that mean slip ups in QC can't happen? No, but it gives context.

Unless the rear sight has a set screw (which it doesn't), then threadlocker should not be used.

 

[user12358]

Unless the rear sight has a set screw (which it doesn't), then threadlocker should not be used.

Dave Dawson seems to disagree with you that thread locker shouldn't be used for permanent installation.

 

[David Mayeur]

Dave Dawson seems to disagree with you that thread locker shouldn't be used for permanent installation.

I've followed Dawson tutorials in the past and have never heard them mention threadlocker. I did a search and their website and see that they recommend using 620 on front dovetails and 262 on rear dovetails and screw on front sights. I use threadlocker on threads, not on flat mating surfaces.

 

[user12358]

I've followed Dawson tutorials in the past and have never heard them mention threadlocker. I did a search and their website and see that they recommend using 620 on front dovetails and 262 on rear dovetails and screw on front sights. I use threadlocker on threads, not on flat mating surfaces.

He talks about the permanent method being using the screw to hydraulically push 262 to lock the sight to the dovetail.

 

[David Mayeur]

He talks about the permanent method being using the screw to hydraulically push 262 to lock the sight to the dovetail.

Because those have a set screw.

 

[user12358]

Because those have a set screw.

The first method he isn't filling up the well with 262 to lock the set screw. He is talking about using the set screw to distribute the 262 under the sight. That just happens to be the easiest way to distribute the Loctite but it can be done without a set screw.

 

[fwrun]

This exact thing happened with my Ameriglo black suppressor sights after my first 300 rounds with the RDS. Drifted way left. The sight was installed by Primary Machine, who cut the slide for the RMR. I used my polymer tipped punch and tapped it center, using calipers to confirm. I then used a toothpick to work superglue into the dovetail, watching it seep under the sight. 1k rounds later and it hasn't moved at all. Worked like a charm and didn't harm the cerakote. Same effect as using 262, which is pretty common in various competition circles.