Different zeros for different optics?

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cybrok

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Hi guys.

It's actually my first post on this forum, so be nice.

I was just watching Travis Haley's "Adaptive Carbine" DVD. He talks about different optics and zeros.

I like his setup with a reflex and iron sights. I can't do red dots due to astigmatism (Never needed glasses, doesn't affect me at all, unless I look through a red dot, looks more like a raspberry than a dot, I am ok with holographic). I love the tech sights on my Marlin 795. So yeah, I like the idea of a reflex for close range and iron sights for longer range.

Question is, would you use the same zero? A 300 yards zero for the iron sights seems like a good idea, but would you prefer to have close range zero for the red dot? (200 yards for instance, where it shots in a 2.5" zone). I don't think the red dot would end up over the front post.

I would use a flip up rear sight.
 
What are you using your optics for?

I haven't seen the video mentioned and would be interested in hearing the logic behind red-dots and iron sights. Can't see how this would be better than say an offset mini-red-dot (or irons) and a 3-?x scope (or just a 1-4x or 1-8x scope) for any use that I can conceive in a run-and-gun context (inferred from "Travis Haley" and "Adaptive Carbine"). The only benefit I see to a red-dot and iron set-up may be weight and cost savings.

Red-dots are great at short range because they tend to be very fast - faster than most scopes in my experience but I know some folks who are as fast with irons as with red-dots. Out past 100 yards they can be challenging to use if targets are much smaller than torso or "A" zone sized. While some might be able to do it consistently, I think 2.5" groups at 200 yards with a red-dot would be quite challenging for most folks and for most ARs (i.e. 1.2 MOA groups) especially if this is shot from prone without bags. Even if the rifle is sufficiently precise, magnified optics will almost always help to achieve more consistent hits at 300+ yards than with irons.

Also, considering that there are 2 zeros for any sight, short-zero and long-zero, a 300 yard long zero for irons will be approximately equal to a 35 yard short-zero, so why would one need a red-dot for that range? If weight is critical, why not get good with irons and drop the red-dot?
 
Just to clear things, he didn't mention using 2 zeros, I was just asking.

I want to put on iron sights because I like them. No other reason. I might change my mind in the future if my eyesight change.

My thought process was that 100-200 yds zero will give you a smaller hit zone under 200 yds. So better for close range?

Now for the long range, let's say you use a scope for this one with an offset optics as you said, can you zero it at 36/300 yds to make holds easier?
 
To shoot at anything, you have to able to detect it first and then aim at it with a useable sight picture. If you can see the targets and the targets are big enough for your choice of reticle , non-magnified system will always be faster.

In general, 10" steel plates can be easily engaged out to 250ish meters very quickly with a 2MOA dot, if you know where they are and see them. If you paint the same stationary targets in green, you will most likely have to use a bino or scope to locate them one by one first. If you move to a 4MOA or 6MOA dot, a 10" steel plate will be much more challenging because the target will be covered.

In all practicality, 300m shooting with iron sight is purely academic. Most people cannot even detect and then identify a 300m target that is not white or orange standing out int he open, without using some kind of optics. If your milk and butter is 300m+, you should get a sight with BDC and quick way to estimate range. The downside is that you will never be as fast as the non-magnified 2MOA red dot under 200m.

Also, shooting a 2.5" group with reddot is possible if your rifle is precise enough, if you are able to optimize a paper target just for the red dot to print groups - but this is not a practical measure of anything in the real world.

Basically, 50/200 is the more practical and realistic zeroing.
 
cybrok said:
Just to clear things, he didn't mention using 2 zeros, I was just asking.

I want to put on iron sights because I like them. No other reason. I might change my mind in the future if my eyesight change.

My thought process was that 100-200 yds zero will give you a smaller hit zone under 200 yds. So better for close range?

Now for the long range, let's say you use a scope for this one with an offset optics as you said, can you zero it at 36/300 yds to make holds easier?
Click to expand...

For IPSC competition I use a scope zeroed at 50/200. With this zero, even if you don't use holdovers/hold-unders your POA won't vary from your POI by more than about 1.5" from 25 yards out to about 200 yards. A 100 yard zero will have a POI to POA difference of about 1.5" at 25 yards and almost 3" at 200 yards (these numbers are approximate and will of course vary with different bullet BC and muzzle velocity). A 36/300 yard zero will have a POI to POA difference of over 4" at 100-150 yards. Most of these stats are largely irrelevant since most shooters/ARs will not be able to hold to this level of accuracy at extended range nor will it matter much in many competition settings.

The size of the group (if this what you mean by hit zone) isn't going to be dependent on your zero, but of your rifle and your ability to be consistent.

If you are going to use a scope then one with a reticle having hash marks or a calibrated reticle with hold-over points for various ranges helps a lot...just overlay the correct holdover on the target and squeeze.

Also a correction, not all zeros will have 2 POIs. A scope zeroed at the apogee of the round will only have 1 zero. For many 5.56/223 loads this will occur at about 100 yards.

See the article below for some great information.

http://www.m4carbine.net/showthread.php?65679-AR-15-Zeros-and-Trajectories
 
Pr589 said:
The size of the group (if this what you mean by hit zone) isn't going to be dependent on your zero, but of your rifle and your ability to be consistent.
Click to expand...

Haley calls it the "combat effective zone". I just didn't think the term applies very well to shooting paper and steel. Let's just say the "POI spread". But you get the idea. PBR for short range optics, zero with hold for long range. Does it make sense at least in theory?

I don't know my ARs, but I know my ballistics.

That was also the other idea behind this: I don't have an AR yet, or red dot, or scope. I probably won't buy everything at the same time.
 
Pr589 said:
If you are going to use a scope then one with a reticle having hash marks or a calibrated reticle with hold-over points for various ranges helps a lot...just overlay the correct holdover on the target and squeeze.
Click to expand...

Not a fan of BDC. Are there Mildot reticles for ARs?

(EDIT: Nevermind, googled it like a big boy)
 
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cybrok said:
Haley calls it the "combat effective zone". I just didn't think the term applies very well to shooting paper and steel. Let's just say the "POI spread". But you get the idea. PBR for short range optics, zero with hold for long range. Does it make sense at least in theory?

I don't know my ARs, but I know my ballistics.

That was also the other idea behind this: I don't have an AR yet, or red dot, or scope. I probably won't buy everything at the same time.
Click to expand...

It sounds awesome in theory, but when you shoot iron sight, holding over means you cannot see the target that you are trying to shoot at because the sight post is blocking the target.
 
cybrok said:
Hi guys.

It's actually my first post on this forum, so be nice.

I was just watching Travis Haley's "Adaptive Carbine" DVD. He talks about different optics and zeros.

I like his setup with a reflex and iron sights. I can't do red dots due to astigmatism (Never needed glasses, doesn't affect me at all, unless I look through a red dot, looks more like a raspberry than a dot, I am ok with holographic). I love the tech sights on my Marlin 795. So yeah, I like the idea of a reflex for close range and iron sights for longer range.

Question is, would you use the same zero? A 300 yards zero for the iron sights seems like a good idea, but would you prefer to have close range zero for the red dot? (200 yards for instance, where it shots in a 2.5" zone). I don't think the red dot would end up over the front post.

I would use a flip up rear sight.
Click to expand...

i don't know why Mr. Travis Haley suggests a 300 yard or 200 yard zero on a red dot, I know he's a super duper captain america operator but that is just next level full retard.
iron sights and red dot zeros are 50 yards
fixed magnification zeros (acogs, elcans, etc) are 100 yards
use your iron sight clicks or your bdc indicator to go to longer ranges.
 
mikethebike said:
i don't know why Mr. Travis Haley suggests a 300 yard or 200 yard zero on a red dot, I know he's a super duper captain america operator but that is just next level full retard.
iron sights and red dot zeros are 50 yards
fixed magnification zeros (acogs, elcans, etc) are 100 yards
use your iron sight clicks or your bdc indicator to go to longer ranges.
Click to expand...

Negative. Elcan C79, OS4, DRs and the ACOGs I have used ignore 100m and are zeroed @200m. Same with irons and red dots. Rough zero at 50m (most people can't shoot so 50m is usually as good as it is going to get), confirm and fine adjust at 200m which needs to be done to iron out height over bore issues.
 
Gunnerlove said:
Negative. Elcan C79, OS4, DRs and the ACOGs I have used ignore 100m and are zeroed @200m. Same with irons and red dots. Rough zero at 50m (most people can't shoot so 50m is usually as good as it is going to get), confirm and fine adjust at 200m which needs to be done to iron out height over bore issues.
Click to expand...

I was going to say, optics such as ACOG/Elcan are zeroed at 200m.
 
mikethebike said:
i don't know why Mr. Travis Haley suggests a 300 yard or 200 yard zero on a red dot, I know he's a super duper captain america operator but that is just next level full retard.
iron sights and red dot zeros are 50 yards
fixed magnification zeros (acogs, elcans, etc) are 100 yards
use your iron sight clicks or your bdc indicator to go to longer ranges.
Click to expand...

Somehow I dont think Travis Haley would recommend a 200/300 yard zero. He was prob talking about the 50 yard/ 200 yard re zero thing. Haley is one of the tops in the game with real world experience so I dont think he would go full retard......except when he worked for magpul. Then that was "look cool as you can to sell DVD's" kind of training.
 
I had iron sights and also a relflex on a 45 deg. rail for coyote hunting. It was a fast combo but the irons were an issue for me at distance and low light plus wooded backgrounds.

I removed the irons and mounted a 4-16 scope. It's a decent combo for low light or distance but the reflex is faster if they bust in on top of me inside 100m which happens while calling. If I can catch movement in the field and track them in with the scope, it works better especially for any needed holdover/hold off when they hang up.
 
Gunnerlove said:
Negative. Elcan C79, OS4, DRs and the ACOGs I have used ignore 100m and are zeroed @200m. Same with irons and red dots. Rough zero at 50m (most people can't shoot so 50m is usually as good as it is going to get), confirm and fine adjust at 200m which needs to be done to iron out height over bore issues.
Click to expand...

The main reason for the 50 m red dot/ iron zero is not because its easier to do, but because doing so will place your shots in the "target" zone (8" upper body) regardless if your shooting at 5 meters or 250 meters. Its a combat zero

Cheers
 
Gunnerlove said:
Negative. Elcan C79, OS4, DRs and the ACOGs I have used ignore 100m and are zeroed @200m. Same with irons and red dots. Rough zero at 50m (most people can't shoot so 50m is usually as good as it is going to get), confirm and fine adjust at 200m which needs to be done to iron out height over bore issues.
Click to expand...

but then the bdc built on the acog and elcan don't work
 
Elian Specter using 62gn NATO ammo out of a 16" barrel is almost perfect with the BDC. Confirmed on many Service Rifle Competitions out to 500 meters.

Rich
 
Different optics have different reticle designs. Most ACOGs come with a 100m aim point, and so is Elcan spectre. That is what the manual said.

On the other hand, if you know how to use a ballistic calculator and with a bit of intelligence, you can formate different ways to zero your sights with different type of ammo.

For example, I zero Elcan Spectre, ACOG and aim point, anything with a 1.5MOA or 2MOA dot, with a theoretical 150-160m zero. That little deviation of 1/2 MOA means nothing for the range and target type that a 5.56 carbine is supposed to use against. On the other hand, you can now do point and shoot within 200m. It an area is touched by the dot, it gets a hole.

Even if you zero a 100m aiming point at 200m, that is only 1.5MOA or 0.4ish mRad of difference. 1.5 MOA of error can be easily made by 50meter'ish misjudgement in range estimate. Shoot high and adjust. It is a waste of effort to worry about or being super anal about "matching the BDC" down to a meter with a 4X optics and a rifle that shoots 1.5 to 2.5MOA. Once it is out in the field, range estimate and some change in angle means one way or the other you need to be fast on your feet to adjust fire. If you need to be more precise, you need a different rig and a laser range finder ( you are good ranging targets)

Final thought, the 50/200 cross over is a 5.56 thing that works with AR15 using a typical bore over sight distance of 2.5". It doesn't work nearly as well with TAVOR that has a much higher sight over bore distance. It is a rule of thumb for most AR15s shooting 5.56, but it is NOT a law.
 
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