ACOG vs EOTech Range Report

[Travis McGee]

Blackbeard, both rifles should be in their prime at 100 yards. To say an EOTech isn't designed for accuracy at 100 yards is foolish.

Remember, I wasn't bench testing for accuracy, but for "combat accuracy" offhand standing, firing 30 round mags at about a one second pace.

Both are "combat sights" touted for speed and accuracy, and 100 yards is surely not "too far" for a 1X EOTech with a 1MOA center dot. If 100 yards, standing offhand semi-rapid fire is "too far" for an EOTech, then everybody should toss them out. If a combat sight isn't deadly at 100 yards, it's worthless, and I don't care how fast it is at 20 yards.

 

[strambo]

The ACOG is a great sight, but had a pretty good advantage in the 100yd comparison which played to its strengths (I did enjoy the write up). I had one in Afghanistan and it was a great all around optic for that environment as I was patrolling mostly the countryside.

I was definitely slower 25yds and in, plus the tritium wasn't real bright at night. I love my Aimpoint H1 that I have on my personal AR for a general combat type sight where I'll (in an HD or SHTF situation) likely be using it close up (certainly no more than 50-100 max). The ACOG really starts to shine at 50 and out, but the most likely (and desperate) circumstance for most citizens would be up close, possibly feet but certainly less than 50 yds in most cases. I want my carbine optimized for the most likely and most time-critical, engagements. The Aimpoiont/Eotech will still enable torso his to 300yds and most soldiers find hitting at range easier with the dots than the irons (but not the 'COG ).

For longer out...I can just have a different gun!

 

[benEzra]

hmm... that's interesting. I have shot eotechs quite a lot, but only put the magnifier in front of my aimpoints, so i didn't realize they might be different. I will try that sometime. i'm still somewhat skeptical about the 'diffraction limited' explanation. thanks for correcting me though.

Taliv, see this white paper, frame 22:

http://www.dtic.mil/ndia/2004armaments/DayII/SessionII/05Gallagher_SmallArms_Sight_Oppurtunity.pdf

Holographic sight provides true point source as aim point
• Dot size limited only by eye resolution to 1 m.o.a.
• Placing 4X scope behind sight magnifies target scene 4X but dot size remains 1 m.o.a.
• Effective dot size is 0.25 m.o.a. or 1" at 400 yards
• Aiming dot provided by holographic sight, placement of magnified scope not critical
• Not true with red-dot sight where image of LED is projected
– If magnified scope is placed behind sight, dot is magnified with target scene – no gain in aiming precision
– If magnified scope is in front of sight, target scene is shifted relative to aiming dot, re-zeroing is required. Long eye relief also severely restricts FOV

With a red dot sight, you're looking at a reflection of a tiny LED, hence the difficulty in making it smaller than about 2 MOA, and when you put a magnifier behind it you magnify the reflection along with the background image. With an Eotech, on the other hand, you are looking at a completely synthetic image generated by a laser interacting with two diffraction gratings, so the central dot can be arbitrarily small.

According to that paper, the dot is a true point source; it is effectively 1 MOA with a Mark 1 eyeball behind it, 0.33 MOA with a 3x magnifier behind it, 0.25 MOA with a 4x magnifier behind it, etc. Your eye will never see it as subtending less than 1 MOA because that is essentially the "pixel size" of the human visual system for that wavelength (it's actually the diffraction limit, but it's a good analogy).

BTW, I found the following pics of an Eotech without and with magnification (I think it's a 557) here:

http://www.defensivecarry.com/vbull...n-discussion/102380-holographic-sights-2.html

No magnifier:




4x magnifier:




Note that the 65 MOA ring is larger, but the central dots are still as small as the camera can resolve them. This particular reticle is a BDC for 5.56x45mm out to 500 yards, I think.

 

[Travis McGee]

BenEzra: Very cool info. I didn't know any of that. Thanks.

 

[strambo]

Ooooh, ahhhhh...

I'm an Aimpoint kinda guy, but that Eotech w/ BDC reticule and magnifier is sweet! I didn't know that about the dot size re: Eotech either, makes sense once the technology is explained.

 

[arizona98tj]

Blackbeard, both rifles should be in their prime at 100 yards. To say an EOTech isn't designed for accuracy at 100 yards is foolish.

Remember, I wasn't bench testing for accuracy, but for "combat accuracy" offhand standing, firing 30 round mags at about a one second pace.

Both are "combat sights" touted for speed and accuracy, and 100 yards is surely not "too far" for a 1X EOTech with a 1MOA center dot. If 100 yards, standing offhand semi-rapid fire is "too far" for an EOTech, then everybody should toss them out. If a combat sight isn't deadly at 100 yards, it's worthless, and I don't care how fast it is at 20 yards.

I don't think anyone was saying that the EOTech can't be expected to perform at 100 yards. I have one on my FNH SLP and can vouch for what it can do at 100 yds off hand.

At the same time, I wouldn't pretend to think that an EOTech is in its "prime" at 100 yards. It certainly is within what should be its functional range....but at its prime? No. That is silly speak.

 

[taliv]

interesting benezra, but doesn't the magnification totally screw up any of the other dots, which presumably are hold-over points for different ranges? they look like they're different

 

[c5_nc]

I think OP missed the point of a 1x, which is target acquisition speed. Two equal shooters engage each other at same time, even at 100yds. The person with the ACOG has a bullet hole in their chest before they have time to center on target at 4x and fire. Yes, so its not as accurate it may be in the stomach or shoulder, etc. There are huge trade offs in speed and any type of short range combat, which is why people mount red dots on top of their ACOGs.

 

[Blackbeard]

If you want a test that shows the EOTech's strengths, try this. Set up ten silhouette targets at various ranges from 5 to 50 yards and different angles & elevations. Now see how fast you can put one hole in each of them with the two different optics. I bet the EOTech comes out ahead.

 

[benEzra]

interesting benezra, but doesn't the magnification totally screw up any of the other dots, which presumably are hold-over points for different ranges? they look like they're different

No, all the dots are all diffraction-limited, and their position relative to the background doesn't change. The only thing the magnifier changes is how big the background looks to your eye. The dots have more space between them as the image is magnified, but POA/POI is independent of the magnification, and (assuming proper zero) the 500-yard dot is a 500-yard hit at 1X, 3X, 4X, or 10X if they made a 10X magnifier. It also doesn't matter if the magnifier is a little off-center, as a hologram can be made parallax free (the only error from being off-center is the offset from the line of sight, but there is no angular parallax).

 

[eye5600]

As others have said, your comparison is apples and oranges.

But sometimes you're making fruit salad. Or, to paraphrase Don Rumsfield, you compare the scopes you've got, not the scopes you wish you'd got.

 

[Zak Smith]

Qualitative breakdown of carbine optics:



article | Fighting Carbine Optics

Pretty much this. A comparison of a unmagnified close combat optic with a magnified medium range optic is essentially meaningless. They aren't meant for the same things, so the obviously will not perform the same when being tested

Absolutely not meaningless- an experiment that is controlled and the only variable is the optic will reveal the speed/accuracy tradeoffs of the optics. Get a rifle, put the optics in some LaRue mounts, and set up a simple course of fire and get to work with a shot timer. This can teach you a lot about your own ability and limitations and those of the equipment. The only "trick" is to do an actual experiment with controls, etc, that will provide the answers to the questions you think you're asking, and not just a set of arbitrary data that is not comparable.

 

[Justin]

But Zak, going out to the range and actually shooting is just so difficult!. It's much easier to grouse about other people's range tests than to actually go out and figure this sort of thing on your own.

 

[statelineblues]

A friend of mine just got his first AR D), and is looking for a sight system similar to the ACOG or EOTech - just not as expensive (he started a new job and doesn't have alot of $$$ at the moment) - any suggestions would be helpful!

 

[benEzra]

A friend of mine just got his first AR, and is looking for a sight system similar to the ACOG or EOTech - just not as expensive (he started a new job and doesn't have alot of $$$ at the moment) - any suggestions would be helpful!

Hmmm. The Eotech 516 is about $440, which is still plenty steep, so if that's out of his price range then I've heard relatively good things about the Primary Arms knockoffs of Aimpoints, and the Vortex Strikefire. The Primary Arms Micro is about $80 (or $108 including a riser for a lower-1/3 cowitness) and the Vortex Strikefire is about $150.

Here's an m4carbine.net thread on the Primary Arms Micro, which is probably the best of the sub-$100 optics, bar none. The customer service is also reportedly quite good.

http://www.m4carbine.net/showthread.php?t=53171

The manufacturer's page:

http://www.primaryarms.com/product.sc?productId=303

You do get what you pay for---it's not as durable as an Aimpoint Micro, the optical quality isn't quite as good, and battery life is 250 hours instead of 50,000 hours---but it's $80-$110 instead of $500. Notice that you'll need the $29 riser to get a lower 1/3 cowitness, or $108 total.

Another decent optic, albeit more expensive (but not necessarily superior) is the Vortex Strikefire.

http://www.vortexoptics.com/product/vortex-strikefire-red-dot-scope-red-dot-only-ar15-mount

m4carbine.net thread on the Strikefire:

http://www.m4carbine.net/showthread.php?t=51173&highlight=strikefire+primary

On the Vortex, it has been mentioned that the red-dot-only version (the one I linked) is better for serious use than the red/green-dot version, because the latter doesn't go as bright and can wash out in bright sunlight.

From personal experience, I'd suggest avoiding all other inexpensive red dots. I tried a $40 Tasco ProPoint from Walmart (zero wandered some, serious parallax issues, the tube coating flaked off inside the tube and scratched the inside of the front lens) and a $45 NCStar reflex sight (built like a toy, matchbox-car-metal battery cover was 100x easier to crossthread than to screw on straight and was almost impossible to avoid scratching the lens with, and wouldn't cowitness). And avoid at all costs the fake Chinese made Eotech "replicas" that are actually just cheaply made red dots intended for Airsoft toys.

 

[Tim the student]

A friend of mine just got his first AR (), and is looking for a sight system similar to the ACOG or EOTech - just not as expensive (he started a new job and doesn't have alot of $$$ at the moment) - any suggestions would be helpful!

I haven't read any reviews of them, but I bet this is a good durable product :http://www.valdada.com/product/81e63ffe-067e-477a-b577-8c2725b2093a.aspx. I was able to get my hands on one from my local guy (who I think was charging $200, but I may be mistaken), and I liked it, FWIW. I can't imagine Valdada putting out crap. Battery life is significantly shorter though.

 

[Avenger29]

A friend of mine just got his first AR (), and is looking for a sight system similar to the ACOG or EOTech - just not as expensive (he started a new job and doesn't have alot of $$$ at the moment) - any suggestions would be helpful!

Tell him to save his money and in the meantime get as much shooting experience with as many different kinds/brands of optics as possible. This is the most practical option. Lots of research + hands on test drives leads one to make better choices.

 

[speaksoftly]

Nice pics benEzra. That Eotech 557 is the exact model I have and I could not be more in love with it. Since the day I sighted it in, I knew I was an Eotech man.