AR-15 sight question

[YosemiteSam357]

I'm looking into my first AR-15, which is an M4 config with a detachable handle, and have a question: Does the front sight post in this setup obscure the view from a red dot or scope? Is the sight removable? Or would I be better off going for a full flat top, no front sight model if I plan to put a r.d. on it?

-- Sam

 

[Mot45acp]

Depending on scope, many co witness with the sight. If it troubles you to see the sights through your scope, then maybe some folding sights are in order.

 

[Vermont]

As I understand it, if you have a magnified optic, the front sight post will be blurry and you will hardly see it, depending on the magnification you might not see it at all. With an unmagnified optic, it might cowitness depending on the height it is mounted at.

I'm not speaking from experience here, but I'm interested to know the answer too because I'm looking into getting an AR. Am I close with my analysis, or am I way off?

 

[MMcfpd]

With a scope the front sight is a grey blur at 3X that, for me anyway, pretty much drops from consciousness when I'm sighting with the scope's reticle. At 4.5X and above it disappears altogether.

With a red dot/holo sight you can set it up with a "perfect" cowitness, where the dot is aligned with the iron sights. That is how I have most of mine. The beauty of the red dot, though, is that if having the dot on the sight post bothers you, you can move your head a little and the dot moves off the sight post but is still on target.

That arrangement bothers some; alternatives include using risers/mounts that position the iron sights in the lower third of the red dot window, or using fold down front and rear iron sights.

 

[cbrgator]

I will speak from experience. My AR is a flattop with a rear folding sight and regular FSB. Mounted to that flattop is an Aimpoint CompML2 which used to be mounted at standard height and is now mounted high. When adding a red dot to the flattop, your best bet is to get a high mount from one of the reputable manufacturers which will provide you with lower 1/3 co-witness. This means that when looking through the red dot sight, the red dot will be basically in the middle of the sight, and the iron sights will still be viewable but in the lower 3rd portion. That way if the red dot were to fail, you could still use the iron sights without having to fiddle with equipment yet it also doesnt intrude on your vision when focused on the dot.

 

[Evenflo76]

Many reddot scopes will co-witness. It can depend on which height rings are used. Also, quality AR optic mounts ( 1 piece designs for scopes ) will have a height that mimicks that of irons. This is done for sighting in purposes.

My cousin uses a Bushnell Holosight on a flattop M4gery with a standard front sight post. The reticle lines up perfectly with the fron post.

Here are some links:

http://www.ar15.com/forums/topic.html?b=3&f=18&t=206233 This has an explanation of co-witness

http://maxicon.com/guns/optics/one_piece/ar15_onepiece_mounts.htm This has a list of popular 1 piece mounts.

I use a Wilson Combat 1" and have a rail gas block ( no front post ) The centerline height of this model is 1.65" for 30mm and 1".

Here is a pic:

 

[Onmilo]

I use a Trijicon Reflex ll sight straight 1X on a flat top with front sight.
The front sight is visible and the yellow dot of the Reflex sight cowitnesses with the front sight by sitting on top of the post like the dot on an i.

I can also use a back up iron sight and it will also cowitness with this apeture. HTH

 

[YosemiteSam357]

Thanks for the info, guys!

-- Sam