Guys,

Today finally done all I need for my first AR MP15 Sport. I went to the range today zero at out at 25 yards with Red dot and Iron sight. I've heard that we don't need the iron sight when using red dot ( Use iron sight if the red dot fail)

Now the newbie silly question:

Do we need the to aim the red dot with the rear sigh???
I ask because ppl said no need the sight anymore with red dot after zero it out for quick aim shoot. Just follow the dot. However, without the rear sight, the dot go over the places when my head moves and the Sport stay the same position.....

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S&W M&P Sport | Ruger SR1911

The iron sights will be for backup if the red dot should fail.Just keep the iron sights folded down and use the red dot.It will take some time getting used to using the red dot only so take your time.Practice and enjoy yourself.

No, you do not need to look through the rear sight when using the red dot. The dot does appear to move if you do not have a consistent cheek weld. This is normal, and one of the advantages of a red dot. You don't have to have perfect technique to put hits on the target.

Fine job, looks good. As for the red dot, once it's zeroed, the iron sights are just a bonus. Where you place the dot is where the bullet goes, that's the beauty of red dot sights.

Good Luck and good shooting.

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SFC, US Army, Retired

Thanks

But The dot moves around when my head moves. SO how can I know where is the right spot? Wish I was in the Military to know all the techniques.

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S&W M&P Sport | Ruger SR1911

Makes no difference. The dot is aligned in reference to the barrel, not your head or eye position. If you had a laser bore sight tool, it would project a red dot on the wall. If you looked through your red dot sight at the same time, at the same distance you zeroed your weapon at, the two dots would essentially appear as one.

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SFC, US Army, Retired

That's the way a dot works. If you're looking through both your iron sights and your dot (co-witness) the dot appears to be in one spot. Fold down your sights, and the dot looks like it moved position. It didn't.

It's weird to get used to, but this is why a dot provides the quickest sight picture. You can keep both eyes open. As long as you can see the dot, you can put rounds on target.

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-John

It is hard to explain, but I'll give it a try. The dot is projected onto a concave lens inside the optic that reflects the image of the dot back to your eye. As you move your head around, the dot will appear to move as well. For the most part, where you see the dot is where the bullet will hit.

You can have parallax issues at certain distances, depending on the red dot, how far forward it is mounted, etc. The parallax errors will be greater when the dot is further from the center of the sight. To combat this, try to keep the dot close to the center of the sight. Typically, in my experience, the parallax hasn't been that much of an issue, and I was still able to stay on target.

That is the beauty of the red dot. You may be firing from cover, or behind a barricade, or some other position where you don't have a perfect stance or cheek weld. Even if the dot is not perfectly centered in the tube, you can still make a hit on target.

Thanks for the explanation guys

I'm not hard headed. But the concept are so weird. the gun steady in 1 position then bullets will go at the same spot. Moving my eyes will get the dot at a 1,000,000 diff targets. How the bullets will follow the dot when the gun stay 1 position????

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S&W M&P Sport | Ruger SR1911

Your head is changing how it looks at the dot, not how the dot is centered on target. The dot isn't really moving, you are, does that make sense?

What distance are you looking at? That is part of the parallax issue. They say red dots are parallax free, but that is not completely true.

For example, if I brace my gun in position to be aimed at a specific spot across the room, as I move my head around the dot follows it. The dot appears to come off that spot that I was originally aiming at, but if I fired, the bullet would still impact that specific spot. Up close, the difference between where the dot is and where the hit will be is exaggerated.

If I move my target out to the 50 yard range and do the same experiment, I see very little to no change in relation as to where the dot appears on the target. The dot could be at the 8 o'clock position in my tube, but it still appears to be center mass on the target.

Remember, the red dot is not a precise optic. It is a quick acquisition, hit on target optic. You can move your head around and still get a hit on a 8 inch plate at 50 or 100 yards. You are not going to stack bullets into a cloverleaf with it.

Previous reply was rather long winded to simply say that the reflective lense is curved. The dot is being projected to the same spot on the lense. As you move around, you are seeing a reflection of the dot at different angles. At short distances, this will appear as if the dot has moved from the original aiming point. At longer distances, the effect is minimized and the dot appears to remain on the same spot on the target, although it has appeared to move in the tube.

Technical knowledge is good, but sometimes a practical example makes things easier to understand. Try this--- Rest the rifle on something. With both eyes open, look down range with the red dot on your target. Focus on the target only. Now move your head a bit from side to side. The red dot should stay right on target and not move around. This is called parallax free. There's always some parallax but it is minimal.

Using both eyes open is how a 1x red dot has unlimited field of view compared to a magnified optic that folks typically focus down the tube only with one eye open. With a 1x red dot, your eye does not have to be a certain distance from the optic as is required with a magnified scope. This gives the 1x red dot unlimited eye relief. Unlimited field of view and eye relief is what makes the red dot a fast target acquisition device. And of course a 1x red dot does not have to be aligned like front and rear sights. Eliminating all these things makes the 1x red dot a simple point and click operation.

1x red dot is also a blessing for aged eyes. Just focus down range... no fuzzy sights.

And now here's something we hope you really like...

While doing as Phil suggested above, with both eyes open, cover the front lense of the red dot sight, where you can not see through the tube. What do you see?

I'm a little late here, but I'm going to say what Phil did only a little differently. I too had trouble gaining faith in my red dot at first. Then I tried a little test and you can do this too.

With the gun on a tripod or bags, aim at a dot/target. It doesn't matter what, just that you know what the dot is on. Now, move your head a little. The red dot will appear to move, but is it still on the target you originally aimed at? It should be.

So, whatever the dot is on is where the bullet will go.

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Freedom isn't free.

You jinxed yourself. Now you'll never be done. LOL.

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-John

Tried. When I move my head a little, the red dot move about 10mm to left or right when my head moves the opposite. No it's not on the original target any more.

Sent from my SAMSUNG-SGH-I317 using Tapatalk

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S&W M&P Sport | Ruger SR1911

Are you doing this at across the room distance? If so, that is the parallax issue that I posted above... In that case, the bullet will hit at the original aiming point. However, 10mm movement? That will still score a hit if aimed at center of mass.

10mm movement that's inside the scope. the real target object is not 10mm but about 30-50 inches. More when the target object is far-er... no its not center mass anymore (if consider human body)

Sent from my SAMSUNG-SGH-I317 using Tapatalk

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S&W M&P Sport | Ruger SR1911

I'm at a loss, don't know what to tell you. If you put the front of the rifle on a rest and place the dot on a target, as you move your head a little while looking through the red dot, the dot will appear to move inside the sight but remains in line with the target. This is the same for me with both eyes open or only looking through the site with one eye. Are you sure that you are keeping the rifle stationary?

At close ranges, 50 yards or less, most of the cheap red dots have parallax problems. Parallax can be defined appropriately to rifle scopes as the apparent movement of objects within the field of view in relation to the reticle.

I will post some pictures in a little while to help with this. At the moment, it sounds like you have a parallax issue with your red dot scope. What model and make of red dot do you have?

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Freedom isn't free.

OK, I think we've already answered this question, but here it is in pictures. I'm using an EOTech 556 which is a Hologram Weapon Sight (HWS) and it's not a red dot, but the use and results are the same.


This is how I set up my rifle:

It doesn't matter what it's pointed at, just so the rifle doesn't move for this test.

Here is the EOTech sighted in on the base of a tree:

Notice that the reticle is just a little off to the left, but the dot in the middle is on the base of the tree way off in the distance.

In this picture I moved the camera just a little to the right, but the rifle was not touched:

Notice that the reticle has moved in relation to the frame of the optic, but that the dot is still at the base of the tree.

This is how your red dot should work. If you move your head, the dot should stay on the target. If the dot is not staying on the target, you have a parallax problem and should consider a different sight or send that one for repair.

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Freedom isn't free.

Lets' make this really easy. Go to the range, shoot using the iron sights with the red dot co-witnessed, fold down the rear sight, and shoot using just the dot while aiming at the same point as you did before. Keep the dot on the target, but with it at a different location in the sight. The rounds will continue to hit the target because that's where you put the dot.

Good Luck and good shooting.

PS... Rastoff, love that sight picture. Now where's that stupid piggy bank?

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SFC, US Army, Retired