Aimpoint PRO Co-Witness

[readyeddy]

I tried googling this question but got mixed answers. Some say that a true absolute co-witness is not possible with the mount and spacer that comes with the PRO, others say it does both absolute and lower 1/3, and others say that you can't just use the mount on an AR because the front sight will cover the entire target . Add to the mix the different front sights that people use, and I'm now confused.

My question is whether the hardware that comes with the Aimpoint PRO will allow an absolute co-witness with a FSB front sight AR, and if so, is that with the mount and spacer or just the mount?

Thanks in advance for any help you folks can provide.

 

[Acera]

Just checked mine.

The front sight and rear sight co-witness to about 1/3 from the bottom with the top of the front sight ears about 1/2 way up.

I absolutely hate it, so went with flip down front and rear BUS. That gives me a clear, unobstructed view.

My Aimpont PRO is installed as it came out of the box, just the ratcheting knob mount with no extra spacer.




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[Steve in PA]

Lower 1/3 when mounted on my Bushmaster. As for the front sight, if it's bothering you, then you aren't concentrating on the red dot. I've had and optic (either Eotech or AIM Point) on my AR for over 10 years, never once had an issue with the front sight.

 

[MistWolf]

I much prefer not having the front sight in my field of view

 

[Chuck R.]

Mine was a lower 1/3rd, but I've swapped for a Larue QD mount.

As for the fixed FSB, I look at it this way, IF things go to chit, it's once less thing to have to flip up. I can literally use my "dead" optic tube as a giant ghost ring rear, and make decent hits out to 50 yards or so just by doing a lower 1/3rd. Practice it sometime, turn the RDS off and sight through the tube. Both of the carbines I have set up for HD have a fixed FSB.

As Steve in PA said, I don't notice the FSB when I'm on the dot.

Chuck

 

[RainDodger]

I don't get what some are saying about not co-witnessing with a stock factory front sight. Here's a picture of an Aimpoint PRO mounted as it comes from the factory, on a S&W AR Sport. Mounted this way, it is absolutely co-witnessed with the factory front sight and the flip-up rear. It absolutely duplicates the sight picture of the back-up sights.

 

[BrocLuno]

Mine is similar. A2 factory front should co-witness. The red dot should be just a bit above the front sight post.

But, the question becomes - what are you trying to do? A close quarters engagement means all you need to do is put the red dot center mass and shoot. Do not worry about front sight in the picture, you have enough outline and peripheral vision with both eyes open to see the actual target. If the red dot goes down, flip up the rear sight and continue on...

If you are trying to shoot scope-style at longer range targets, you need to move your optic higher to get the front sight down out of the optical sight data path (mil-dots, stadia, ranging circles, circle-dot, whatever ...). That will require going to at least 1/3 co-witness (lower 1/3), and maybe further down than that. So you will have to have your optic on a different mount block. You need to contact someone like LaRue to get that worked out and have your sight heights written down measured from the rail top...

Some folks will put their irons on a 45* side mount so that the optic is clean and clear. This is especially true when they have a higher magnification optic like a ranging scope (say a CMR). If they need the irons, they will just tilt the rifle to access them. Very quick.

Or, some folks put their optic on an off-set "side mount" style so that the irons are always dead center. This is because they have an A2 standard front sight/gas block (me for instance). Many rifles were run hard in WW-II and Korea with side mounts. Been doing that for a long time... This is just a modern version.

Still comes down to what you want to do?

 

[readyeddy]

I thought the hardware that comes with the PRO includes both the mount and a spacer. If so, is absolute co-witness achieved with both the mount and spacer or just the mount?

 

[RainDodger]

The Aimpoint in the picture came just as pictured - there is a spacer (it's the piece with the transverse holes through it) between the mount and the sight. The instructions that came with it said that the spacer would be best removed for use on something like a shotgun. The co-witness is WITH the INCLUDED spacer, which is already installed on the sight. Hope that helps.

 

[Acera]

Ok, just looked at mine closer. It has the same piece of metal with the eight holes like the picture posted above by RainDodger. Pretty sure it is the separate piece (spacer) as the color is a bit different that you are talking about. Mine is mounted the same way as the above picture. Set up like that when I opened the box and mounted in on my pistol. Probably could remove it and put the sight closer to the barrel axis if I wanted. Not exactly sure how it would work out with the irons, but pretty sure the irons would co-witness in the top of the field of view and not in the lower 1/3 as they are now (when flipped up). Might be even harder getting down to that level for a good sight picture. Someone else will have to confirm that as I have no interest in getting more obstructions in my sight view than I have now.

Is this the answer to your question you are looking for?


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[readyeddy]

Yes, the answers are very helpful and my question is answered. Now I just need to find a good deal and a reputable seller so I can finally own a durable RDS!

Thanks to everyone.

 

[Theohazard]

Here's a picture of an Aimpoint PRO mounted as it comes from the factory, on a S&W AR Sport. Mounted this way, it is absolutely co-witnessed with the factory front sight and the flip-up rear.

No, it's not an absolute co-witness, not exactly. The centerline of an Aimpoint PRO with the spacer is a little bit above the iron sights on a standard AR-15. It's not as high as a true lower-1/3 co-witness, but it's not as low as an absolute co-witness.

The standard accepted AR-15 sight height above the bore is approximately 2.6". The height from the bore to the top of the rail is 1.25". This means the standard sight height is about 1.35" above the rail. However, on their website Aimpoint lists the height of the PRO with the spacer at just over 1.56" above the rail. And without the spacer they list it at just under 1.19" above the rail. So the PRO is either going to be mounted above or below your iron sights, depending on whether you're using the spacer, but you're not going to be able to get an absolute co-witness either way.

I thought the hardware that comes with the PRO includes both the mount and a spacer. If so, is absolute co-witness achieved with both the mount and spacer or just the mount?

The answer is neither; you'll either be above it or below it depending on whether you're using the spacer or not. I have an LMT with fixed iron sights and an Aimpoint PRO with the spacer installed. I just now looked down my iron sights and confirmed that the center of my PRO is indeed above my iron sights. And I didn't try it, but it sure looks like if I removed the spacer it will put the center of my PRO below my iron sights, just like the specs say.

 

[BrocLuno]

Slightly above is good. If the Dot is running use it. If the Dot goes out, just run the Irons

Theohazrd, next time you go to the range, would you check to see what the actual sight picture is at 50 yds with say an 8" bull ...

My bet is that the dot will be center bull, and the irons will be at 6 o'clock hold - everything where it should be

 

[readyeddy]

I bought my PRO and got it sighted in and did some shooting.

The sight picture is as described by Theohazard.

I didn't shoot an 8" bull at 50 yards, but a 10" gong at 100 yards places the front sight about a foot below 6 o'clock when the dot is centered in the tube and holding center target.

 

[readyeddy]

I'm going to share this just in case there's someone out there that's as mentally challenged as me.

I bought an Aimpoint transparent front lenscover to replace the existing cover. So I try to remove the existing cover by turning and pulling it off. After about a half an hour of struggling and internet research, I discover that the tube has a groove and the lenscover has two sections of footing that lock into the groove, so turning the lenscover doesn't do anything.

The solution was to use my thumbs to push the hinge part of the cover out of the groove, and the whole thing slid off easily.

Some people on the net recommended using a hairdryer to heat up the rubber, but that was a waste of time.