EOTech Reticle

[captbilly]

I have had a Bushnell red dot sight for several years (my son got it for a science project), and while it seemed kind of cool it did have some parallax errors and the plain dot reticle didn't seem to solve some pretty obvious problems with close in vs. long shots. I have finally had some time to play around with my EOTech XPS3-2 and I am really getting to like it.

But my question is this: with simple dot reticles, like on the Aimpoint (and even some EOTech models) how do you deal with close in vs. long range shots? On the EOTech you sight in the dot (on the XPS3-2 it would be the upper dot) at medium range. You can use 25 yards as a sighting distance and be within a few inches high or low out to several hundred yards. When you go very long distance shooting, which is clearly not what these were designed for but you still might have an occasion to need it, you go to the lower dot which is set for more like 400 yards. In very close (7 meters, 22 feet) you go to the bottom of the 65MOA circle and are right on target. So again, how do you do accurate shooting at 7 yards or 400 yards with a single dot reticle?

I had just one other observation. In another post a few weeks ago someone was suggesting that one should mount their red dot sight as far forward on the rifle as possible so that the dot would be as small as possible. I have checked this on both my Bushnell reflex sight and the EOTech holographic sight and the size of the reticle does not change at all as you move it closer to or away from your eye. It seems to me that having the sight as close as possible has the great advantage of making it much more likely that you will see the reticle immediately upon picking up the rifle. If the sight is way out on the handguard and you are only slightly off your normal cheek weld, you won't see the reticle at all (it will be off the side of the sight window). For example with the EOTech if I mount the sight as close as possible on the receiver I have a very wide field of view where I can still see the reticle, and since the EOTech is completely parallax free it makes no difference to accuracy if your cheek weld is correct or not.

[brando]

Mounting electronic optics over the barrel has proven to be problematic if you shoot often. The heat affects the durability and the optics will fail. Of course, if you're just plinking and your life doesn't depend on it, go right ahead.

The original EOTech innovations were the holographic method of displaying the reticle and the 65/1MOA reticle. At the time, the more common RDS used a single large (4-7 MOA) dot and while this large dot was a vast improvement over iron sights when acquiring the target, it obscured human sized targets at 200 yards and beyond.

The 65/1MOA reticle improves this situation by adding the large ring to help get you on target quickly but retains a small 1 MOA dot for shooting at longer range (ie it's small enough not to obscure targets). On top of that, the ring can be used for simple drop compensation AND lateral leading of moving targets.

The sight is not designed for shooting at extended range - it's primarily a close range RDS - but the configuration of the reticle will assist in shooting those farther distances than say a single dot RDS. The newer XPS3-2 reticle helps further in that regard. But as for using a single dot RDS, you're pretty much stuck to how you zero and it requires holding above the target at longer ranges (which is really just a matter of training).

[HK Dave]

I had just one other observation. In another post a few weeks ago someone was suggesting that one should mount their red dot sight as far forward on the rifle as possible so that the dot would be as small as possible.

The idea behind putting the EOTech further forward is to allow you to have both eyes open. When you have both eyes open and the Eotech sits forward... your mind creates the illusion of the reticle floating ahead of the gun. However I'm talking about the Eotech sitting on the forward part of the upper receiver... i don't know that it makes sense to have it on the front handguard as your viewing window becomes greatly diminished in size.

[Merc1138]

You can shoot both eyes open with an eotech all the way to the rear. The point of putting the eotech forward on the rifle, is so you can have a magnifier, iron sights, or NV device behind it. You can see the reticule just as well with it forward or back.

You can adjust the elevation just like you'd adjust the elevation with irons. 1 click = 1/4 moa. Besides, red dots aren't "meant" for long range shooting. Sure, they can be used, even irons can, but if you want a red dot to take the place of close range sights and a long range scope you're probably going to be disappointed. This is why you'll see some people with a scope, and then a small red dot mounted to the top of the scope, or off to the side at an angle.

[vintagearms]

You can shoot both eyes open with an eotech all the way to the rear. The point of putting the eotech forward on the rifle, is so you can have a magnifier, iron sights, or NV device behind it. You can see the reticule just as well with it forward or back.



One of the benefits of having the EOtechs in the forward position on the receiver is your field of vision is not solely on the reticle (your supposed to be looking thru the reticle at the target anyway), but peripherally on possible other targets/innocents.

[Merc1138]

One of the benefits of having the EOtechs in the forward position on the receiver is your field of vision is not solely on the reticle (your supposed to be looking thru the reticle at the target anyway), but peripherally on possible other targets/innocents.

I understand that, but it is not required to do so. I have no issues with my field of vision if I mount my eotech all the way forward(battery compartment hanging over the handguard), or all the way to the rear(where I prefer it) up against my folding buis. The FOV difference in the eotech is due to how open the sight is(not having the tube) compared to a red dot in a tube chassis(even then you can mount those red dots wherever you want and the dot is just as visible).

[HK Dave]

You still get the holographic effect with it all the way to the rear? Maybe my brain is malfunctioning but i don't seem to... it just looks like the reticle is in the glass instead of many feet ahead of me.

[Merc1138]

Yeah, if I take it off and set it down and hold my eye as close as I can get to it, I still get the effect of the "floating" reticle while I focus on whatever it is I'm looking at. A red dot isn't dependent on distance from your eye. Hell, you can cover the front of a red dot, look through it with your right eye but have both eyes open and you'll see the dot appearing in front of what you're looking it.

[captbilly]

You still get the holographic effect with it all the way to the rear? Maybe my brain is malfunctioning but i don't seem to... it just looks like the reticle is in the glass instead of many feet ahead of me.

The effect you are describing is actually not even peculiar to holographic sights, red dots sights produce this as well, but in either case it is independent of the distance from your eye to the scope. Even a properly adjusted magnifying scope will actually produce the effect but on the high powered scope eye relief will be a very limited range.

The thing that makes the holographic sight unique is the way in which the reticle is generated. In a typical red dot the reticle (red dot) is projected with lenses and is subject to parallax errors (although as I mentioned in the OP Aimpoint claims to have found a way to correct for parallax for all ranges), but with a holograph there are no lenses and no parallax errors at any range. This is inherent to holographs and is not subject to any careful adjustment that could be knocked loose over time. The reticle does seem... different when viewed with the sight far from the eye, but that is simply related to the narrower angle of view available as the sight moves away from your eye.

[brando]

This is exactly why when you've contorted your body to fit behind a twisted 6" wide pipe sticking out of the ground as some booger eater is dumping rounds your way from a rooftop down the street, you can make accurate shots with the..worst...cheek weld...ever.