A better ZERO From my DPMS LR-308

[J.Boyette]

Guys,

Went to the range today. Using my DPMS LR-308 16" rifle running a 40yd ZERO, I did not adjust for distance I held center-mass and let the bullet print on paper. Once done, I read the reticle and wrote down the hold and fired the 2nd shot with that hold to confirm it was on. This new ZERO is the way to go for practical marksmanship and it works like a champ. So now I have a solid DOPE in 10yd increments.

The holds are simple.

Key:
Hold Under = HU
Hold Over = HO
<span style="font-weight: bold">I</span>nches in <span style="font-weight: bold">R</span>elation to <span style="font-weight: bold">L</span>ine of <span style="font-weight: bold">S</span>ight = IRLOS

010yds 1.4milrad HO IRLOS 1.5” low
020yds 0.8milrad HO IRLOS 1.1” low
030yds 0.2 milrad HO IRLOS 0.6” Low
040yds ZERO IRLOS 0.0
050yds ZERO IRLOS 0.0
060yds 0.5milrad HU IRLOS 1.1” high
070yds 0.5milrad HU IRLOS 1.3” high
080yds 0.5milrad HU IRLOS 1.4” high
090yds 0.5milrad HU IRLOS 1.6” high
100yds 0.5milrad HU IRLOS 1.8” high
110yds 0.6milrad HU IRLOS 2.4” high
120yds 0.6milrad HU IRLOS 2.6” high
130yds 0.6milrad HU IRLOS 2.8” high
140yds 0.5milrad HU IRLOS 2.7” high
150yds 0.5milrad HU IRLOS 2.6” high
160yds 0.4milrad HU IRLOS 2.3” high
170yds 0.4milrad HU IRLOS 2.1” high
180yds ZERO IRLOS 0.0
190yds ZERO IRLOS 0.0
200yds 0.1milrad HO IRLOS 0.75” low
210yds 0.1milrad HO IRLOS 0.8” low
220yds 0.1milrad HO IRLOS 0.8” low
230yds 0.2milrad HO IRLOS 1.75” low
240yds 0.2milrad HO IRLOS 1.75” low
250yds 0.4milrad HO IRLOS 3.6” low
260yds 0.5milrad HO IRLOS 4.75” low
270yds 0.6milrad HO IRLOS 5.8” low
280yds 0.6milrad HO IRLOS 6.0” low
290yds 0.8 milrad HO IRLOS 8.4” low
300yds 1.0milrad HO IRLOS 1.08” low

Using this 40yd ZERO on a SWS for deployment setting from trunk to FFP is the way to go it looks like. The worst offset was at the 10yd line but even that came at the 6 o'clock location in the T-zone. By aiming center mass as it stands right now I can shoot within a 6" target from 0 to 240yds. The highest place of my bullet is at 130yds and its right at 2.8" high then drops off at 240yds at 1.75" low.

So what nice about this is that with different target sizes my life gets real simple.

Target face surface area aiming center-mass:
0yds to 240yds POA / POI high low with in 6”
0yds to 250yds POA/POI high – low with in 8”
0yds to 260yds POA/POI high – low with in 10”
0yds to 270yds POA/POI high – low with in 12”
0yds to 280yds POA/POI high – low with in 14”

Granted, running any ZERO distance you can do the samething to a point. But the ability to engage target sizes at distance drops off.

From what I have found, the 40yd ZERO gives the best of both worlds. As a LEO Sniper lets say, you can engage all the target sizes above as a deployment ZERO.

Once onsite you can dial in the right DOPE for the suspects engagement zone, this ZERO lets you move from point A to point B with the ability to raise the hit rate % drastically over a 100yd ZERO.

John

 

[DMack]

Re: A better ZERO From my DPMS LR-308

I am doing the same zero with my PWS MK214. My data is almost identical. I shot this over the past two days with positive results.

 

[Scottmilk9]

Re: A better ZERO From my DPMS LR-308

John,
Interesting data. Thanks for sharing.

I could plug this into patagonia, but to be honest Im to lazy, what is your drop lets say 700yds with the 40yd zero?

 

[J.Boyette]

Re: A better ZERO From my DPMS LR-308

DMack,

Hell this is a part my idea any yours. Its cool to see us tracking the same DOPE from FL to NC.

Scott,

Same drop as with any ZERO. Gravity pulls the same no matter what your scope says.

But I have not shot past 300yds, and computers lye on how a bullet gets from point A to point B.

So I do something wild, and CRAZY

I SHOOT MY RIFLE!!!!

And record as I find out how the 168 flys.

But on exbal its got me at the following.

400 1.8milrad
500 2.9milrad
600 4.2milrad
700 5.6milrad
800 7.2milrad

this is exactly .2milrad flatter then my 100yd ZERO from 200yds to 800yds.

nothing more then a simple slide down some of the numbers.

Soon I will be at Butner With my partner and shooting to 1000yds with this 16" rifle and recording as we go.

Thanks for the post.

John

 

[Scottmilk9]

Re: A better ZERO From my DPMS LR-308

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: J.Boyette</div><div class="ubbcode-body">Scott,

Same drop as with any ZERO. Gravity pulls the same no matter what your scope says.

But I have not shot past 300yds, and computers lye on how a bullet gets from point A to point B.

So I do something wild, and CRAZY

I SHOOT MY RIFLE!!!!

</div></div>

I guess my question should have been more detailed. I was wondering if there is any advantage out past 500yds with your 40yd zero. But after seeing your exbal, it doesn't look like it.
Thanks for the lesson in physics and Newtons law though.
I'll stick with my 100yd zero as I go to Oklahoma to shoot in two weeks(when I shoot my rifle)

 

[J.Boyette]

Re: A better ZERO From my DPMS LR-308

Scott,

All kidding aside,

I posted this over at LF so enjoy.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">
This is the deal here lets look at competition first.

Lets say I am facing a stage with 6" 8", 10" plate steel all unknown range.

When I size up the stage, all I need to do is range the farthermost targets "200yds and past" As I eye ball them.

I am now saving a huge amount of time and raising my score!

The 6'" plates I aim center mass from 0 to 240yds, the 8" plates I can do the same to 250yds, 10" to 260yds.

Even if some plates are past 200yd mark, I can still hold / dial for them. But the plates that do fall in the range are DOWN FAST!!!

This lets me blaze down for a quick time. A hit is a hit on steel right? It counts if its low, right, left or center mass, the hit is still points! Even if I have a scoring ring setup, I just adjust and do the correct hold and send it.

So every hit counts from the end ranges of the target sizes. That sounds like precision rifle to me, hitting what you aim at every time!

Now take this to the operational level.

Lets say I am a LE Sniper and I get called out. I know as I deploy with my rifle walking in to a unknown situation I can make a head shot from 0 to 240yds on a flash target.

Once I get to my FFP I laze the target zone and dial in to the correct DOPE for that distance.

Once again, this ZERO gives me a advantage over the basic 100yd ZERO.

Have you ever asked yourself or others why the 100yd ZERO is used? With the avg LEO Sniper engagement being right at 51.4yds why not ZERO to a 40 or a 50yds and dial from it?

I am not advocating that blazing away is precision rifle. In the same context what level of accuracy is acceptable for unknown situations?

I know that running the most simplest system, for the most complex situations wins every time.

aiming center-mass of a 6" Point blank strike area for a 6.5" x 10" target makes more since then to remember my holds SHOOT RIGHT THE FUCK NOW!!!!! type situation.

Think about it.

John
</div></div>

To me, and others that see the same thing I do. People are going to change to this or a ZERO that offers more then a 100yds ZERO.

I have thought about it alot, why do people ZERO at 100yds on the max ord? No one has told me a solid why.

Have a great trip ok.

John

 

[Scottmilk9]

Re: A better ZERO From my DPMS LR-308

John,
Thanks, I have no idea why zero'ing at 100yds besides all the paper stuff we do in competitions.

I like your 40yd zero for a law enforcement purpose, it seems like a natural fit, but i have no experience in it as I know you do.

Thanks again for sharing and good luck to you also.

Hope to see you at the Bash this year.

 

[J.Boyette]

Re: A better ZERO From my DPMS LR-308

Scott,

Wish I could make it to the Bash. One day I plan on making it. I know Jacob and crew do good things, and it always good to see different ways to skin the cat.

Thanks

John

 

[DMack]

Re: A better ZERO From my DPMS LR-308

For me... A LE Marksman running my SBR AR10 platform this makes my flash hits lethal within my operating range. Once I am in my FFP and know the exact distant to Target... Come ups are come ups... Holds are holds. I find that my bullet drop is less drastic past 250 than it is with a 100 yard zero.

I shot out to 700 yards today and was dialing less than my 100 yard data. This is due to max ordinate being above LOS... VERY SOLID for me and my needs.

 

[J.Boyette]

Re: A better ZERO From my DPMS LR-308

As you guys can see, my DOPE is not 100% filled out but the rifle is doing well.

I am headed to the range tomorrow to work on marksmanship with this rifle.

This thing is a tack driver and I will post up some pic's of how it performs later on.

John

 

[Scottmilk9]

Re: A better ZERO From my DPMS LR-308

Good looking gun John!!

 

[GSPKurt]

Re: A better ZERO From my DPMS LR-308

Very nice rifle...

 

[Luke]

Re: A better ZERO From my DPMS LR-308

Good idea here.

I think the main reason the vast majority of folk zero at 100yds is it's convenient, since most sight-in ranges are 100yds, and it's linear and easy to remember things in 100 yard increments.

Not that it's hard to remember a different set of numbers for a 40yd zero...just more intuitive to do it the conventional way. Maybe more people should go with the 40yd zero, works better for snap shots and keeps your brain from getting lazy