Until I can decide on an upper tier sight, I decided to go ahead and get an OKO W in the meantime. I can always use it on something else if and when I decide on which ACOG or other alternative.

My question is, BUIS read and front sights can I use to add to a front rail gas block to cowitness with this site if it is mounted on the flattop?

I just got my 16" OLY upper with a FF tubular handguard. I probably won't go with a SIR or other high dollar handguard - I just don't need it for my application (hunting/ranch rifle).

Do I have to mount a rail out on the handguard and reposition the OKO to be able to cowitness and if so, again with which back up sights?

Why would you need to cowitness?

As long as you can see through the OKO and use the irons if the optics crap out, you are good to go.

Cowitnessing for accuracy or whatever isn't needed.  Yes, it can help with initial zero, but that's a minor, minor benefit.

You should be able to use the BUIS and front sights just fine if mount the oko directly on the flattop.

Thanks for the reply. One reason is that I want to be able to see! I mounted an Armalight front sight that I had laying around and the BSA red dot I have mounted just to get the new upper/barrel broken in is right in the middle of the sight - not anywhere near the post, let alone the top of the post.

Meaning that the front sight is way too high and in the way of my being able to see a clean sight picture. So whether cowitnessing - which I may want to do since again, this is a ranch/hunting rifle and lighting conditions are rarely ideal - or just using the back ups in case of battery failure or whatever, I want to be able to use them both without removal of either.

I have an OKO mounted directly to my flattop. The tip of the front sight is just barely above the center of the OKO. It cowitnesses fine. I use the OKO exclusively and have the rear back up folded down and it works great. If I want to use the BU sight I just flip it up and look through the OKO.

You can get the SC-4 quick detachable protective cover that will set the OKO a little higher.

I believe any back up front or rear sight will work just fine. I would recommend a flip up rear sight, cuz I like just using the dot. Any flip up front sight should work just fine too if you have a railed gas block. The standard front sight also works (it is in the field of view of the OKO but there's plenty of room to use the dot).

You will not experience the same problem with the OKO as you did with the BSA. These are mounted to low. I have a tasco propoint and in order to properly cowitness and use the dot I had to put it on a swan sleeve(raise the sight .5 inch).

Edited to add pic of rifle.

[img]http://www.imagestation.com/picture/sraid51/p44914d4822bbb299040690fe6a6e7b0f/fca678f9.jpg[/img]
[img]http://www.imagestation.com/picture/sraid51/p2060dbd7dbd10835eff7f5c87e286939/fca678f8.jpg[/img]

Ridge:  "The tip of the front sight is just barely above the center of the OKO."

Are you saying that the red dot of the OKO is just below the front sight?  Doesn't that get in the way?

Thanks for the input Ridge. The OKO, ARMS #40 and Bushmaster BMAS front flip sight are all ordered and on the way.

I'll see how it works out and if need be, I can order the SC-4 cover later.

Yes if you were to center the dot directly in the middle of the OKO's lens, the tip of the front sight would be in the way.  All you have to do is move your head up, or the dot slightly above center and it works fine (remember the dot does not need to be centered with these reflex sights). There's plenty of room to shoot with. Using the SC4 mount would probably allow you to directly center the dot(but it isn't necessary, unless it really bugs you). When I'm shooting I don't even notice it. I focus on the dot and everthing else dissappears.

Markbo:

"Until I decide on an upper tier sight"? Puh-leeze. The OKO *is* my "upper tier" sight; I got rid of an Aimpoint COMP-M XD and a C-More Scout when I got my OKOs. Never looked back.

I run both of my OKOs in the SC4 QD mount/roll cage, directly on the flat-top. When used with an ARMS #40 and a standard front sight post, everything lines up and co-witnesses perfectly.

You can also use the SC3 mount, if you don't need the QD capability of the SC4. Both add the ruggedness of the roll cage, and bump the sight body up about 1/2" in height. Without the mount, I found the sight to be a little low for my preferred co-witness (irons visible in the lower 1/2 of the scope FoV). But if you like your irons to line up in the exact center of your scope FoV, you may want to skip the mount.

Good luck with your OKO!

By upper tier sight, I was referring to an ACOG or similar. I consider them another tier above the OKO or any reflex sight for that matter.

Markbo:

I've not shot with an ACOG but have handled them fairly extensively... I don't think they're 4x the product the OKO is, so it's hard to justify spending 4x the money.

hmmm... interesting. I have not handled any of them personally, so I can't say, though I have thought from the start that the price on the ACOG's and similar sights were a bit steep.

But by another tier, I was thinking more in terms of the next step up in type of optic - a reasonably small telescopic sight with some sort of built in ranging capability (completely useless in a non-magnifying reflex sight with my poor eye3sight) and lighted reticle.

I think that is a tier up from any reflex sight, though I must say I do agree on the price issue.

But then again, many things that are shooting/ gun related tend to cost too much. Maybe a lighted reticle hunting scope would be a viable option for my use. We shall see.