Unorthodox AR sighting method

[Rittmeister]

I've been doing some thinking. I'm setting up an AR for shorter-range, quick shooting with a red-dot. I have a Primary Arms advanced micro dot, which I like a lot, but I can't help wondering about another item I've got laying around.

The gun will also have Magpul backup sights; I have a mount for the PA sight that sets everything up for absolute co-witness. What I find is that I don't much care for using the sights through the red-dot. I could also set up for lower 1/3, and that option is on the table...

... BUT, I also have a Burris Fastfire III in the safe. I've already tried it on another AR with Burris' own AR-F3 mount and liked it; using two eyes it's got a great field of view 'cause you're not even looking through a tube and it's really easy to shoot with. For mounting though I'm having a possibly silly idea - I'm thinking about mounting the MRD directly to the top rail on the gun, which if I'm correct would allow the flip sights to be used over top of the little red-dot.

Anybody have an opinion on this? The only drawback I see is that it'll be very low to the gun but I'm not sure that'll really be a problem when it comes to the shooting.

Any input appreciated.

 

[MistWolf]

I once mounted a scope to an AR that turned out to be quite low. It was awkward and uncomfortable.

However, you won't know for certain until you try it for yourself

 

[wanderinwalker]

Seconding what MistWolf wrote, a scope or red dot mounted UNDER the sight line of the irons on an AR-15 is going to be too low to be truly useful. Try it and see, but I suspect you won't leave it that way for long.

Come to think of it, I actually like the slightly higher sight plane of a lower-1/3 cowitnessed red dot. Probably because it reduces the scrunched up feeling I get behind an AR peep.

 

[JamieC]

I have Holosun on my AR now, (an NC Star was on it originally...it worked!), both were set up absolute co-witness, never really noticed the front sight when using them. One good thing about the NC Star was the quick release mount. If it went bad, pop it off, flip up the rear BUIS, GTG.

 

[chicharrones]

Try it and let us know what you think.

I believe it might work well for someone with a smaller head, and therefore shorter cheek to eye dimensions. Particularly a child. As long as they could handle the gun safely, of course.

 

[Tirod]

The AR has a lower bore axis when held compared to traditional rifles with a lot of drop in the stock. Those older rifles also had the sights mounted directly on the barrel and receiver. The AR elevates them because the straight line action forces the bore down to the shoulder level.

So, high sight line AR, low sight line traditional, with a stock that raises it right back up to eye level.

Mount your sights and optics to your eye sight line and it will be comfortable shooting.

However - the closer the shooting range, the less we need sights. I would forgo adding a red dot at all as it requires you to get your head down to see thru the "tunnel" where you can pick up the view. Same for sights - at 21 feet you still have to account for offset and having the sights on top of the red dot means the issue remains. Most using AR's at close range don't use the sights, they look over them - at the projected laser dot which indicates a more accurate point of impact.

To accommodate the need for a light, I see the use of a green "big bore" laser illuminator that puts a 6-12" spot at 21 feet a better choice. It not only facilitates identifying the target, which is critical in home defense, it also indicates a point of impact. It's a 2moa gun aimed at a 18moa target - a large green 6" spot brightly illuminated center of mass is going to deliver a center of mass hit. In the priority of stopping an intruder, a hit is more important than improving it one or two numbers as if it were a scored competitive exercise. It's hard enough to get a hit - handicapping your performance with long range sighting devices that actually narrow your field of view and force you to adopt awkward postures seems highly counterproductive. So what that you get the improvement on paper from maybe an 8 to a 10? It's less than 21 feet. You need a hit to stop and the incremental difference of placing the bullet two inches closer to center of mass is highly arguable when life and liberty are on the line.

I have iron sights on my HD gun because I use it for close range deer hunting and no device projecting a beam of light is allowed. But - at home - I'm thinking a green light over 200 lumens with a projected spot from 6 to 12 inches at hallway distances is the way to go. Most I've found will do that in daylight, too.

Self defense in close quarters also means that there are times when you need to fire the weapon but cannot be directly behind the sight line in a narrow tunnel of vision to accurately place a shot. With a projected beam indicating the hit zone it's much more likely and with practice can even be faster.

 

[Arizona_Mike]

With the right risers, all is possible. I think you will find such a lot height uncomfortable, esp as your primary sight.

The fast fire with it's own Weaver base is about 0.827" (21mm) from top of the rail to the dot. A lower 1/3 cowitness optic is going to be about 1.60-1.66" depending on manufacturer. I've seen a lot more variation in what manufactures call absolute but it is in the neighborhood of 1.40-1.45".

I've never seen a riser less than 0.5" and some are actually 13mm (.512").

A 15-16mm riser should get you to ABSCW (sight height). This one should work perfectly: https://www.amazon.com/UTG-3-Slot-A...0_1?ie=UTF8&psc=1&refRID=1E610NQN9C1TENK03PK4

You can also use a backup siting system on 45 degree angle mounts and just tip the rifle toward you slightly for quick close shots. It's very instinctive.

Mike

 

[Zerodefect]

Mini red dots directly on the rail won't work. You'll need a riser.

Lower 1/3rd cowitness for the win.