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308 zero?

MonsTeRZeRo762

Private
Full Member
Minuteman
Jun 4, 2010
6
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42
Dumas, Tx
Im needing some input for a zero on Dpms 308 24" matchtarget barrel, optics is a NF 5.5-22x56mm npr1 recticle with .25 MOA turrets hszstop mounted on a Larue spr4 1.5 now my question is do i use top hash for zero so I can maximize full range of my elevation, or do I just use thE center of the recticle, 168 gr bthp match from hornady is what I'm slinging.
 
Re: 308 zero?

Center of reticle for POI. your zero depends on your shooting habits. I like a 200 yard zero on my P-308 because I use it for hunting, so I'm point blank from 0 to 250 yards.
 
Re: 308 zero?

If you zero at 100 yards, re-zero your windage at 200-300 yards. The reason for this is that as a rule, you'll typically get more deviation from shooter error in windage than you will in elevation. Zeroing wind farther out allows you to see and compensate for these deviations better. Obviously you don't want to do this when its windy though.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BattleAxe</div><div class="ubbcode-body">If you zero at 100 yards, re-zero your windage at 200-300 yards. The reason for this is that as a rule, you'll typically get more deviation from shooter error in windage than you will in elevation. Zeroing wind farther out allows you to see and compensate for these deviations better. Obviously you don't want to do this when its windy though. </div></div>

I do not hold to this for the simple fact that wind will have a greater effect as time of flight increases.

I zero wind at 100 unless I have an incredibly high full value wind. Then I may bring it in and zero out my wind at 25 yards. Precision has less to do with range than it does with the size of your aiming point and your ability to see it.

My reason for a 100 yard zero is simply that all corrections are "UP". If you zero at 200 and out, then some will be up and some will be down. I feel that it is easier to teach and remember that any number you memorize will be a positive elevation correction.

If you hunt, then I can see the value of a "point blank" zero. However most of the shooting I do requires greater precision. I can SWAG the range and hold a proper correction with a more precise outcome.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LoneWolfUSMC</div><div class="ubbcode-body">I do not hold to this for the simple fact that wind will have a greater effect as time of flight increases. </div></div>

I think you misunderstood me LW. My method is geared more towards a more inexperienced shooter which I'm assuming the OP is or he wouldn't have asked the question. I wouldn't tell you how to zero your rifle. The logic behind what I said is this....

We don't zero our reticles to put a single round in a particular spot. We zero our reticles to put numerous rounds as close to POA as possible...We're dialing out variation. Variation from ammo, chamber/case temperature, barrel, and all the little mistakes we make as shooters (trigger, breathing, etc).

When you print a group during zero you dial the reticle to move the center of the group to POA, and as you know...that center may not even have a round through it, yet that is our zero. The size of that group represents variation from all sources mechanical and human.

Most people look at their groups and judge them purely on size but I took the time to examine mine over a period of 2 years. What I found was that I had more variation latterally than I had vertically even during no wind conditions at 100 yards. It was just a guess on my part but I assumed that the reason for better elevation control was due to the rifle being braced. In other words...if you're on a decent bipod and the stock is properly braced on a bag, monopod etc, its harder to shank one vertically than it is to shank one laterally, since lateral control is less dependent on equipment and more affected by shooter movement such a a poor trigger squeeze.

I started zeroing windage at 200 yards to increse the size of the groups and make it easier to see that lateral variation, which can be tough when zeroing at 100 since my rounds are stacked tighter. Remember...I'm zeroing the windage knob at 200...<span style="text-decoration: underline">not</span> correcting for wind. I only do this in zero wind conditions. What I found by doing this is that my windage is more accurate at long range.
 
Re: 308 zero?

Wait...what?

Do I understand this correctly? Since the shooter wiggles at 100, you are of the opinion that it is best to zero for the wiggles at a distance of 200 or even 300 yrds - where wiggles are more pronounced?

If this is done b/c they are inexperienced - what are the chances the wiggle is to the same side each time?

How does a guy ever learn to read wind and make holds at a long range if he has a built in degree of slop in his dope?

Maybe I missed something.

It is like offset club heads - your swing is shit and it is why you slice, instead of learning how to actually swing the club, just use this. However, if you ever really do learn how to swing a club you will hook everything.



The OP should zero both the E and W at the same distance and learn proper fundamentals.


Good luck

 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mo_Zam_Beek</div><div class="ubbcode-body">How does a guy ever learn to read wind and make holds at a long range if he has a built in degree of slop in his dope? </div></div>

Unless you put every shot you take in the same hole when you shoot, <span style="text-decoration: underline">you</span> my friend have slop in your dope.

Either way its not something I feel like arguing. Just ignore it if you don't see the logic in it. I won't cry.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MonsTeRZeRo762</div><div class="ubbcode-body">What's op? Old player, old pimp, operator? </div></div> Original Poster, in this case that is you because you're the one that started the thread.

As for your scope having enough internal travel to get you max range, you have 100moa of total travel and a flat base. In a perfect world that will put you at center giving you ~50moa of available elevation adjustment remaining after a 100yd zero, give or take a couple moa. You'll have enough to get you way out there before you'll ever have to switch to reticle holds for elevation. You should have no problem with everything inside 1k yds until you start hitting sub-sea level density altitudes in the winter.
 
Re: 308 zero?

I would use the 100 yard zero on the center of the retical unless you never shoot less than 200 yards.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MonsTeRZeRo762</div><div class="ubbcode-body">Im needing some input for a zero on Dpms 308 24" matchtarget barrel, optics is a NF 5.5-22x56mm npr1 recticle with .25 MOA turrets hszstop mounted on a Larue spr4 1.5 now my question is do i use top hash for zero so I can maximize full range of my elevation, or do I just use thE center of the recticle, 168 gr bthp match from hornady is what I'm slinging. </div></div>

Center of reticle at 100-yrds. With a 168gr you probably won't be shooting that at 1k+ in which case you'll have more than enough elevation with the NXS.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BattleAxe</div><div class="ubbcode-body">I think you misunderstood me LW. My method is geared more towards a more inexperienced shooter which I'm assuming the OP is or he wouldn't have asked the question. I wouldn't tell you how to zero your rifle. The logic behind what I said is this....</div></div>

I understand what you are saying. However I don't agree with it.

An inexperienced shooter is going to have more trouble with a zero at 200 than at 100. Mirage will be more of a factor if you are using a precise aiming point and high magnification. Wind will be a greater factor as well. Anything that will throw off a zero at 100 yards will throw it off more at 200, 300, etc. Magnifying errors in the system does not generally assist in showing you the center of a shot group.

The number of shots fired is really the key to the precision of the zero. I have at least one rifle that I can zero with one shot. I know the level of accuracy it is capable of. I have others that I would not trust to that because I don't know if the shot I fired is to one side or the other of the accuracy potential of the rifle. For those rifles I may fire three or more shots.

The shooter must also be cognizant of "chasing the zero". This is where the shooter keeps making zero adjustments that are inside of the rifles accuracy potential. If you have a 1 MOA capable rifle, then it doesn't make sense to keep dialing on that last 1/4 MOA when you know the next shot may be 3/4 MOA off of that. You need to shoot a group. Determine the center. Dial it on and leave it be. The less accurate the rifle, the more shots should be fired in the group.
 
Re: 308 zero?

Put that was I now see your point and I realize that I'm using way too many rounds to get a zero. My 100 yd groups were so tight that I couldn't tell if the edge shots were on point or fliers, so I'd verify at 200 to finalize my zero since the group would spread slightly and allow me to better read it. I likely shouldn't be shooting more than 2-3 rounds and I was using 5-8. You just saved me some ammo.
 
Re: 308 zero?

I would go with the group and zero for 100 and use the center on the reticle. If you want to zero at 200 just do that to and make a chart for your scope adjustment....simple and easy.
 
Re: 308 zero?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bchibbs</div><div class="ubbcode-body">I like 100yd "0" for elevation and 200/300yd for windage.</div></div> Just wondering, do you have that backwards?
 
Re: 308 zero?

I consistently zero elevation on my M110 at 300 meters, from the factory M118LR 175 grain is POA=POI @300 meters.

I do not understand why any shooter would want a 100 yard zero when ballistacly this method is flawed. US ARMY FM 3-23-10 US ARMY Sniper School field manual is clear, the 300 meter zero is the ideal zero range for a 308 rifle.

Redmans is right on the money.
 
Re: 308 zero?

I use either a 300 or 500 m zero caliber dependent. But I use almost exclusively holdover/under. If you know your bullet flight it's a lot faster to shoot multiple ranges and hold inside the reticle...

As far as using the top of the duplex it's a great idea. I've done that a bunch with a NF. The only thing is you need to know your true milling power if you plan to use holds. Unless you have first focal plane.