I was talking with a guy and he said he would not use a AR15 that was not zeroed for him. For the purpose of this conversation it was limited to a hostage rescue type scenario.

Is there any validity to his claim? I belief if it’s zeroed is zeroed. If you use a lead sled type device and zero the rifle how can it not be spot on when you shoot? Is this like golf where you know you have a slice and try to play the slice, but every so often you hit the ball correctly and now your off the fairway?

I agree that in theory if a rifle is zeroed, it's zeroed. But I also agree that I'd never use a rifle for a hostage type scenario unless I'd shot it and verified the zero myself. There's always a chance that someone didn't properly zero the rifle or the way they torque the rifle on the bags that it wouldn't be perfectly zeroed for myself. I won't even use someone else's rifle for hunting unless I've shot it off the bags myself.

I've seen rifles occasionally shoot to different POI's for different people, with no sight adjustment having been made. The way the rifle is mounted, positioning of the eye behind the sights, maybe something else. Trigger technique maybe. IMO your friend is exercising appropriate caution.

For HR work, yes I agree. For general liability purposes, I agree. But, practically speaking, inside of 50 there won’t be enough difference to make a hit a miss, or a miss a hit.

Commonly, we do “battle field pick up” training and out to 50, people aren’t off paper because of sighting difference.

quote:

Originally posted by gpbst3:
If you use a lead sled type device and zero the rifle how can it not be spot on when you shoot?

I agree with the other posters that for maximum accuracy the individual should zero a rifle himself, and that brings up the issue of zeroing with something like a lead sled.

Unless one is going to always use a lead sled for whatever purpose the gun is zeroed, i.e., hunting, competition, etc., a lead sled zero may not be accurate. Such a heavy, rigid rest will affect how the gun recoils and that will be different than when shooting in a way that allows the gun to recoil normally.* Some of the difference may be minimized by how the shooter normally fires the gun or when shooting guns with light recoil, but it can be significant.

* That, BTW, is not universally accepted. There are many Internet posts that disagree entirely and state that it doesn’t matter how a rifle is zeroed: zeroed is zeroed. On the other hand, I have seen statements by people who evidently know much more than the average bear about precision shooting who say the exact opposite, and those are the ones I choose to believe are correct.

I read one description of an extensive, well-documented test that demonstrated that point of impact shifts are possible even when shooting using a bipod on different surfaces such as soft dirt, grass, and concrete. I have found the same to be true myself in personal experiments. If such a small difference like that can affect POI, I can readily accept that going from a lead sled to shooting normally can affect things as well. As for the people who are convinced otherwise, many people are simply wrong about many things they believe, but in the end we are free to rely on our beliefs however we want.

We had armory guns and you were allowed personal guns. The armory gun you had to zero on and record your dope. You would draw that weapon for your shift and dial in you dope. You were supposed to zero out your gun at the end of your shift. Most guys purchased their own and had a confirmed zero. The range master would record your serial number and also your dope on the range ticket when you qualify. I would have no hesitation about firing any of our weapons but for a precision shot I would only shoot my own.

quote:

Originally posted by gpbst3:
I was talking with a guy and he said he would not use a AR15 that was not zeroed for him.

Is there any validity to his claim?

Many people repeat this, I have heard it myself.

IMHO, no. Unless one of the shooters doesn't get behind the rifle properly and has induced parallax into the equation. Or one of the shooters has introduced some other shooter created error in the process.

The basic system of an optic on a rifle is fairly simple. (Ignoring the amount of optical engineering involved.) It's an x-y coordinate.

Zeroed is zeroed until shooter A does something differently than shooter B.

A professional LE officer doing hostage rescue work should however, absolutely do the due diligence of maintaining their own weapon and their own zero. If for no other reason than another person my do so improperly or inadequately.

quote:

Originally posted by IndianaBoy:
The basic system of an optic on a rifle is fairly simple. (Ignoring the amount of optical engineering involved.) It's an x-y coordinate.

Zeroed is zeroed until shooter A does something differently than shooter B.

A professional LE officer doing hostage rescue work should however, absolutely do the due diligence of maintaining their own weapon and their own zero. If for no other reason than another person my do so improperly or inadequately.

Bingo

When competent shooters get behind rifles that were correctly zeroed, the zero doesn't change. POI doesn't change. With minor exceptions of sling pressure or pressure on the supporting device, POI doesn't change when shooting positions change -- for competent shooters. The following link is from a few years ago, when Snipershide did on-line training with Jacob Bynum -- who runs Rifles Only. People who don't shoot at Jacob's level won't agree with the results. People who shoot near Jacob's level do agree. It's all about the fundamentals.

Online training - rifle shooting positions

For my purposes the zero is conditional? My Western hunting rifles are 200yd zero, and from there I can get pretty damn close out to 400 just from experience. However deer rifles are +3” at 100yd zero. That puts 3 different rifles with 3 different zeros. I pretty much know but again I’d hate to explain it to someone else.

I understand your friends position. I also believe in a scoped rifle it should not matter from shooter to shooter. Iron sights can be subject to hold.

A particularly large agency in NC in a particularly liberal area does a range-zero for all their ARs for patrol officers, and the rifles are checked out daily. That zero is checked maybe once a year.

I've not heard of any issues. And if there was a documented liability involved in that method I have no doubt that it wouldn't be done that way.

A proper zero with an optic is non user specific.

With iron sights there might be a little tiny difference, little... tiny....

Given that, I always want to shoot it for 2 reasons:
1: most people cant actually properly zero anything
2: Knowing No 1, checking allows removal of a bunch of ambiguity.

We require everyone to qualify their rifle directly from the trunk of the car as it gets carried, with no verification of zero. sometimes the results are interesting

quote:

Originally posted by car541:


We require everyone to qualify their rifle directly from the trunk of the car as it gets carried, with no verification of zero. sometimes the results are interesting

In the days before optics were common issue outside of specialty units, I would have officers with carry handle guns that left the range with a 50 yard zero. The rear A2 drum and front sight would have witness marks in paint pen.

The next year they’d show up to range with the same rifle…….. 10-12 inches off. I obviously complained because these were duty rifles. Admin in the day “fixed” the problem by having me schedule in sufficient time at the beginning of the range block for zeroing. Completely missed my objection to the “problem”.

Today, getting caught with a zero problem will get you sent home and a write up. Since the change in admins, we teach all officers to understand how zeroing works in depth and hold them accountable for the condition of their rifle. Back in the day we called them “click beggars” because they would fire a group and look at the instructor for how many “clicks” they should add. Now, they figure it on their own and are comfortable making adjustments. I know around here that may seem trivial but in Copland that’s a BFD.

In precision rifle and pistol shooting, you zero for the conditions you will shoot by duplicating those conditions as best you can. And you have to be consistent in everything else.
Even your position and grip can change your zero. I can shoot a string. Put the gun down to load a new mag. Pick up and re-grip, and the next string might move a little or a lot because I did something different in the grip or something else.

quote:

Originally posted by gpbst3:
I was talking with a guy and he said he would not use a AR15 that was not zeroed for him.
For the purpose of this conversation it was limited to a hostage rescue type scenario.

Is there any validity to his claim? I belief if it’s zeroed is zeroed.

Yes, zero is zero but you can't fault a guy to doubt anyone but themselves in a life or death shot.
It's more about the confidence factor than anything mechanical.

quote:

Originally posted by chongosuerte:
A particularly large agency in NC in a particularly liberal area does a range-zero for all their ARs for patrol officers, and the rifles are checked out daily. That zero is checked maybe once a year.

I've not heard of any issues. And if there was a documented liability involved in that method I have no doubt that it wouldn't be done that way.

This is a great example of a point I was trying to make with this guy. A large or even a small PD does not have the resources to assign a rifle to each officer. Your given a rifle which had a range zero, there is a very good chance you will not get the same rifle every day. Would you not take the rifle because you have not confirmed the zero?

This message has been edited. Last edited by: gpbst3,

If it's zero, it's zeroed, yes... sort of. But what does that MEAN? That's the problem. Is it going to hit right at the tip of the front sight at 50 yards? 25 yards? 100 yard? Under/behind the sight? ("Combat sight" ) A couple inches high? "Belt buckle hold"? I would REALLY want to know what ZEROED meant. But then, most NON SHOOTERS (and most LEO's fall into that category) probably wouldn't even notice a difference one way or the other.


I've seen plenty of guns "zeroed" (though mostly handguns, but a couple rifles) to compensate for bad shooting habits, yanking or heeling.
It's a hangup any time I look at a used gun for sale, I look at the sight and say "that rear sight is way off center. Is there a problem with gun , or was it with the shooter? Do I take the gamble?" Either one, the previous owner thought it was zeroed.

And I think that’s the crux of it.

Rifle zero is a rabbit hole that you can go down and spend hours collecting data. A good rifle with good ammo will have shifts in zero due weather to a shooter that can recognize it.

Most can’t. So, the topic of zero will net you a wide range of responses. I really don’t think any are wrong.

quote:

Originally posted by cas:
If it's zero, it's zeroed, yes... sort of. But what does that MEAN? That's the problem. Is it going to hit right at the tip of the front sight at 50 yards? 25 yards? 100 yard? Under/behind the sight? ("Combat sight" ) A couple inches high? "Belt buckle hold"? I would REALLY want to know what ZEROED meant. But then, most NON SHOOTERS (and most LEO's fall into that category) probably wouldn't even notice a difference one way or the other...

I failed to mention in my original post the rifle is equipped with a red dot sight with a 50 yrd "zero". Is it safe to say to red dots don't have a combat or holder over/under. Point of impact is point of aim taking in your barrel sight relationship.

quote:

Originally posted by gpbst3:
I was talking with a guy and he said he would not use a AR15 that was not zeroed for him. For the purpose of this conversation it was limited to a hostage rescue type scenario.

Is there any validity to his claim? I belief if it’s zeroed is zeroed. If you use a lead sled type device and zero the rifle how can it not be spot on when you shoot? Is this like golf where you know you have a slice and try to play the slice, but every so often you hit the ball correctly and now your off the fairway?

Perhaps he just poorly worded his response.

At a previous employer we re qualed and trained quarterly. Prior to these training days we "Confirmed zero" to have confidence that our equipment had not been bumped or damaged in the daily routine and subsequent rough handling our M4's were subjected too on a daily basis.

It was understood by all that with proper training and technique....zero'd is zero'd. We actually used to use each others equipment from time to time to instill confidence that they would work. I never missed because someones zero was....off.

I've experimented quite a bit with this over the years. For IRON sights, yes there can be a noticeable difference in POI based on each individuals perception of the orientation of the front and rear sights. For OPTICS, the POI will be consistent.