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Discussion Starter · #1 ·
Hello. I recently acquired an AR-15 in 5.56 NATO and put a Leupold VX-R Hog (1.25 (ish) - 4) scope on her.

As a bolt and lever enthusiast, I'm not used to having that big, tall, front sight in the scope's view.

How can I explain this. Uhm, it bothers me to see the AR-15 front post moving from left to right while acquiring the target. So, you can see the open leaf/front post move away from the center of the scope cross hairs while you are lining up your shot. Doesn't appear to affect accuracy, near as I can tell. It is distracting, also, because you are seeing the blurry leafs/post move to and fro from center. I'm shooting from a rest so I'm not saying I'm wobbling around but sometimes I take my shot and the front post is in the scope and it looks WEIRD because it's off slightly.

Is this normal? No problem? Ignore it like I have been? Or should I correct somehow?

Groups are FINE, so I guess that's all that matters but I'm wondering if I need to adjust my technique with that HUGE front sight distracting my eye...

I don't know, it just is really weird having that blurry iron sight in the scope picture since I can see the center post and it's not lined up with the cross hairs on the scope....

Probably a silly question but thanks for reading.

--James
 

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The front sight will appear to move in your scope field of vision due to optical parallax. When the scope is adjusted for parallax at its designated range, say 100 yards, the reticle is at the focus point within the scope. At ranges other than the focused range, the reticle will appear to move relative to the target as you move your eye in relation to the ocular lens (eye piece). Normally, the apparent movement is not noticed because it is so minute and the magnification is not great. Target scopes of 15, 20 or greater power have an adjustable ocular lens which lets you adjust the parallax for different ranges as required. Here, the magnification is great enough to cause error in aiming if not adjusted.

In your case, the rifle's front sight appears to move because it is very far away from the point of parallax adjustment. It is distracting but as long as you ignore it when making your final lay, it will cause not accuracy problem.
 

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Discussion Starter · #4 ·
Ok, cool, thanks. Something else to learn.... I'm used to adjusting for parallax on rimfire scopes so I can understand the concept of this "issue" meaning I will ignore this focal plane (did I say that right?).

Thanks for the explanation, it was bothering me.

--James
 

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All kinds. Enamored of their mechanisms! Worked as an engineering
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Turn it into an asset. If the front sight is always in the same place when you pull the trigger you will be assured of a consistent cheek weld. My guns that pick up the front sight with a scope the image presented is almost a ghost image. AC
 

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I'd recommend sending the upper to Adco, have them remove the factory combination front sight gas block, and pin on a low profile gas block. Alternatively you might ask them if they can machine off the sight portion of the combination sight tower gas block, I think they might be able to do that and save you some money. Then have them install a lightweight free float rail, something like a Troy or BCM KMR depending on your budget. Top it with a flip up back up sight like the Magpul, and no more distraction, unnecessary weight, and you're free floated. I really like that KMR, and the polymer Magpul sights, after having the standard A2 stuff for a long time. A cousin of mine has the lightweight Troy rail (TRX I think it's called), which is nice, as well, I give that one the thumbs up.
 
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Some people can ignore the front sight, while others are distracted. (I'm in the latter category.)

The front sight can be cut down without having to remove it. And there are free-float handguards available that clamp on to the standard barrel nut (so that it wouldn't need to be removed either). Centurion handguards are one example:

https://www.centurionarms.net/index...task=category&id=5:c4-rail-systems&Itemid=336

If you're not comfortable doing the work yourself, Adco (as miatakix mentioned above) can do the work for a reasonable price and quick turnaround.

https://www.adcofirearms.com/shopservices/
 
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