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Discussion Starter · #1 ·
OK, we all know that the standard Glock is not "zeroed" in the factory. The test fire is just function check. But here is my question.

A conversation with some friends brought this up even though we all change out for aftermarket, we are curious. Is there intent in the design for the sights out of box to be set at a certain distance?

A standard Out of the Box G19 or G23 (actually it would be interesting for all models and Gen's) with factory sights (no optics) what is the rough point of aim/impact distance?

We figure the design itself, based on the dimensions of the pistol and height of the sights there would be an "expected zero distance". With manufacturing I would assume some sort of consistency in sight installation. So, where is the "expected" zero distance based on the dimensions, sight height, etc.? Of course different ammo as well as bullet weights, etc. would change this. But we would assume the engineers involved would have had some sort of intention around this. 5 yards, 7, 9, 20, 25, 50? Or even what people have seen on the first range trip. I plan on trying to get anyone I know to start tracking to compare. :)

I hope that made sense. Also, factoring in that it is not done purposely you would not rely on it as a true zero by any stretch.
 

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While my guess would be around 15yds (Glock would measure in meters). The armorers manual notes that each rear sight option (6.1mm, 6.5mm, 6.9mm and 7.3mm) represents about ~61mm in bullet impact at 25m (about 27 yards). The fact they know that and report it makes me think they at least tested at 25m.

If you run a ballistics calculator like gundata.org on 9mm ammo, you'll see the difference between a zero at 15yds and 30yds is pretty negligible, so they could have used something else when designing the sights and still get pretty much the same result. If I put 27yds (25m) into gundata.org I get the data for 15yds so I used 30yds to compare against.

For the typical self defense calibers, the distances they would practically be shot at are going to be within point blank range (distance the bullet will hit a target without compensation for drop). A Glock front sight is ~.5" above center of the bore so at 0yds you'd be .5" low but at 5yds with a 15yd zero you would be .27" low and not get more than 1/2" high or low until over 40yds. Same with a 30yd zero.

I checked .40S&W at 15yds against the 9mm data and they were pretty close, .40 starts dropping a little sooner but not enough to justify a different zero.
 

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Discussion Starter · #3 ·
Thank you for that information. Very interesting. A lot of this conversation came from how a few of the guys were getting good grouping out to 15 yds (3-4 inches) but as soon as they tried 25 yds they were not hitting paper. Most of the guys were teasing about their horrible shooting. Much more colorful words where used. LOL

Complete geeking out below and in denfensive shooting would make little difference for most people but interesting.
I may be completely over thinking it. But that variance (2.4 inches for each rear sight and 3 changes) you have a possible barrel angle variance of ~20+ degrees. Used fuzzy off the top of the head math. Where your example above is "assuming" a 0 degree variance. That the barrel is parallel to your line of sight. But changing the rear sight you are basically mortaring your barrel. It is canted several degrees upward from your line of sight. Regardless of the math, the idea is that there could be circumstances (specific handguns) where you could get decent groups out to 15 meters/yards (the shooter will notice the POI is a little higher than POA. But reaching out to 25 meters/yds you could end up off paper and have to hold over. Or am I up in the night? Complete off the top of my head with very little to no math involved.

Regardless, I appreciate you entertaining my crazy question on the engineering and design.
 

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I can completely geek out on this stuff but it’s been a few years since I dug into it so I’m not remembering everything (getting old and forgetting more than I know).

You can pretty safely assume that if the size of the group is changing it’s likely the shooter. Going from 10 yards to 25 yards is not far enough to make a significant change in where the bullet hits but it is far enough to make it really hard for a shooter to hit the same spot repeatedly.

I was talking to a co-worker about a match I had just shot and they asked my opinion about what to do if we ever had an active shooter? I responded “stay 25 yards away”

If we take the shooter out of the mix, whatever size group was shot at 10 yards should be nearly the same size group at 25 yards just at a slightly different height on the target.

To answer the question about “some guns” - with the same ammo going from 10 to 25 yards, there would have to be something really odd about the gun to make POI be more than an inch or two different. Standard 9mm ammo is point blank range from 0 to over 30yards - meaning the bullet is not going to move more than 1/2 inch up or down over that distance. I think there would have to be something defective about the gun to cause a much larger change.

Once you start approaching 50yds though you will have to adjust for bullet drop as handgun rounds start to fall fast beyond that.


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for example on social media and in text messages and emails, to mean that you understand people may have a different opinion or experience than yours:

 
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